Types of Parasites

Types of Parasites Chapter 1 General Introduction 1.0 Introduction 1.1 Fish Parasites Parasitism is an obligatory association between two distinct species, in which one species parasite is dependent on its host for nutrients and shelter (Elmer Glenn, 1961). The parasites can be divided into two groups which are ectoparasites and endoparasites. Ectoparasites are found on the external surfaces of the host such as skin, fins and gills, while endoparasites usually hide within the internal tissues or organs in the host (Cheng, 1986). Fishes acts as hosts to a wide variety of parasites such as the protozoans, platyhelminthes, acanthocephalan, nematodes and crustaceans (Lim, 1987). Parasites are typically smaller than their host. A distinct host usually found to be infected by a group of parasites (Zander, 1998). The chemical and physical factors which are either in micro-environment or macro-environment play an important role to determine the distribution and density of parasites (Cheng, 1986). Parasites show a preference among different age groups (Zander et al., 1993), sex of host (Lim, 1987) or according to host density and behaviour (Cheng, 1986). Remarkably, parasites have a distinguished ability to deal with the normal physiological and structural changes of the host, for example, the peristaltic movement and intestinal mucosa (Cheng, 1986) for survival, and starting their parasitism phase. Apart from that, the presence of parasites commonly irritates the host, causing immunological change (Lim, 1979) and may eventually cause death (Zander, 1998). Parasites penetrate the hosts tissue, causing chronic body system problems to the host. Moreover, the irritation site will initiate secondary infection by micro-organisms to the host (Cheng, 1986). 1.2 Specific parasite Gobies play a role as main host and transmitters (Zander, 1993) of parasites. Varieties of protozoan, helminthes, mollusks, crustaceans have been described as parasites of fish (Lim, 1987). They are able to reproduce either sexually or asexually. Some species of parasites have specific attachment to enable them to hold onto the host for food, transport (Cheng, 1986) or shelter (Elmer Glenn, 1961). The phylum Platyhelminthes consists of a large group of free-living invertebrates but most live as parasitic species on or in other organisms. There are 3 main classes under this phylum, namely, class Monogenea, class Trematode, and class Cestoda (Solomon et al., 2002). Monogeneans are typical gillworms (Bunkley-Williams E. H. Williams, 1994). Some species attach themselves on the body surface or invade into the inner organ of aquatic species (Reed, Francis-Floyd Klinger, 1996). Monogeneans have a series of hooks that enable them to attach on the host (Reed et al., 1996). They usually inhabit the gill and feed on skin mucosa (Lim, 1987). Reed et al. (1996) mentioned that a monogenean, Dactylogyrus sp., usually attaches itself to the gills of freshwater fish. It reproduces by laying eggs, while Gyrodactylus is typically found on the skin and fins of fish. This parasite produces live young or can be described as viviparous during its whole life. Digenea was formerly described as digenetic trematodes and this species of flukes usually has at least two hosts in their life cycle (Smyth, 1962). The parasite usually has a terminal opening mouth with a sucker which is subterminal or ventral. It may or may not have an oral sucker (Yamagutti, 1958). They are particularly found as endoparasites in the digestive tract, but are sometimes found throughout the inner organ systems of vertebrates (Yamagutti, 1958). The adult digeneans are commonly hermaphroditic but reproduction still requires two worms. Digeneans have a complex life cycle with two to three intermediate hosts (Cheng, 1986). Cestode is a parasitic flatworm or commonly known as tapeworm (Solomon, et al., 2002). An adult worm consists of a scolex which maybe armed with suckers and sometimes hooks for attachment on host (Solomon et al., 2002); and a strobila which is a linear series that be formed by one or more segments (also described as proglottides) which contain reproductive structures (Yamagutti, 1959). Most of the cestodes are monoecious and each proglottid has a male reproductive system and a female reproductive system. Both self and cross-fertilization will take place in cestode (Smyth, 1962). Nematode is commonly called as round worm (Solomon et al., 2002) that can infect a vertebrates eye, mouth, alimentary system, body cavity and the other parts (Smyth, 1962). This species can also be found as a parasite of many species of fishes. Some species parasitize plants and are described as an important agricultural pest (Campbell, 2002). It is smooth and consists of a cylindrical body, a pointed tail and cuticle layer surrounding its body (Solomon et al., 2002). Nematodes are typically dioecious. The female is generally larger than the male (Cheng, 1986). Apart from that, nematode life cycles differ depending on the species of the nematode (Smyth, 1962). 1.3 The Family of Gobiidae The members which form the family Gobiidae are known as gobies. It is the largest family of marine fishes and consists of two hundred genera (retrieved from Wikipedia). The members of the Family Gobiidae have their own special characteristics. They have a cylindrical body and the pelvic fins usually form an adhesive disc (Maurice Anthony, 1993). This species usually inhabits the shore in shallow bays and estuaries and also freshwater swamps and lakes (retrieved from Wikipedia). Some species are restricted to coral reefs, rocky coast, sandy, mangrove swamp or muddy beaches (Murdy, 1989). 1.4 Oxudercine Gobies (Mudskippers) The mudskippers are known as ‘ikan belacak, ‘ikan tembakul or ‘ikan belukor in Malay. The members of the goby family classified as mudskipper species based on body traits and behaviours (Murdy, 1989). Oxudercine gobies are described as the members of mudskippers (Murdy, 1989). There are thirty four species from ten genera found throughout the world (Murdy, 1989). They are Apocryptes, Zappa, Pseudapocryptes, Apocryptodon, Parapocryptes, Oxuderces, Scartelaos, Boleophthalmus, Periophthalmodon and Periophthalmus. Only seven genera of mudskippers (Periopthalmodon, Periophthalmus, Boleophthalmus, Scartelaos, Oxuderces, Parapocryptes and Pseudopocryptes) were found along the Selangor coast (Khaironizam, 2004). According to Khaironizam (2004), Cantor (1849) had identified five species of mudskippers while Koumans (1953) had noted eight species in Malaysia. Apart from that, there were four species already reported by Macne (1968) and five species were described by Berry (1972). He also mentioned that Murdy (1989) stated 11 species of mudskippers in Malaysia while Takita (1999) had studied 12 species of mudskippers (refer to Appendix A5). The mudskippers are euryhaline and semi-terrestrial species (Clayton, 1993). They have a rounded body and united pelvic fins. They also have a pair of protruding eyes and one to two rows of teeth in the upper jaws. Besides this, they can survive for a long time above water and move on land. Commonly, the males are smaller than the females. The mudskippers usually feed on crabs, insects, and other small organisms (Clayton, 1993). There are several adaptations that allow the mudskippers to survive successfully out of the water. Their bronchial chamber can fill up with water which allows them to walk on land for up to several hours. They spend much of their lives out of water and are able to undergo osmoregulation as well as oxygen uptake via their skin and gills (Clayton, 1993). They are abundant in muddy areas or mangroves. Oxudercine gobies often build mud towers around their burrows as refuge from predators (Clayton, 1993). The mudskippers have certain economic importance which provide substituted fishery for the period of torrential rain in some coastal countries. These fishes are commonly eaten in China, Taiwan, India and some parts of Malaysia. Nowadays, the mudskippers are also used as feed for aquarium fish (Clayton, 1993) 1.4.1 World Distribution of Mudskippers Mudskippers can be found around the tropical world as well as in the coastal regions of Asia, from Indonesia to Borneo (see 3). A few species are also found in Africa and Australia, whereas none are found in the new world (refer to Appendix A1). 1.5 Literature Reviews on Gobiid Parasites (refer to Appendix A7) There is too few research on parasitological studies of mudskipper in the Asian region. Most of the studies nowadays concentrate on the behavior and ecology of oxudercinae gobies (Khaironizam, 2004); taxonomic and cladistic of the oxudercine gobies (Murdy, 1989); and the nitrogen excretion of mudskipper in water and on land, the growth of mudskipper, habitat of mudskipper and osmoregulation system among this species (Clayton, 1993). Mhaisen and Al-Maliki (1996) mentioned that Myxobolus pfeifferi (Sporozoa), Diplozoon sp. (Monogenea) and Neoechinorhynchus sp. (Acanthocephala) were found in dark-blotched mudskippers, Periophthalmus waltoni, from the mudflats of the Khor Al-Zubair estuary. A new record showed the heterophyid (trematode) had served Boleophthalmus pectinirostris and Scartelaos sp. as second intermediate host (Sohn et al., 2005). Clayton (1993) indicated that cestode, agamofilarial and acanthocephalid cysts have been described as parasite in Periophthalmus koelreuteri (Pearse, 1933), Periphthalmodon schlosseri and Boleophthalmus boddarti (Khoo, 1966). Besides, the larval ascarid nematodes infected Periophthalmodon schlosseri (Khoo, 1966). Pseudapocryptes lanceolatus were found to be infected by parasitic copepod, Gnathia sp. A larval cestode was also described by Pearse (1932) in Periophthalmus modestus. A study by Choudhury and Nandi (1973) did not establish any parasitic infection on Boleophthalmus boddarti and Scartelaos histophorus. The intestinal flagellates were also noted by Pearse (1933) in Boleophthamus boddarti. The bacterial flora had been observed by Morii and Kasama (1989) to be in the intestine of Boleophthalmus pectinirostris and Periophthalmus modestus. In West Africa and Singapore, a new species of acanthocephalan was detected in Periophthalmus barbarus and Periophthalmus schlosseri. Eighteen Gyrodactylus species were collected from gobies of the genus Pomatoschistus and the host-parasite relationship was discussed (Huyse et al., 2003). Geets et al. (1999) found that three gobies (Pomatoschistus minutus, P. lozanoi and P. pictus) were infected by Gyrodactylus arcuatus in the North Sea and noted that Gyrodactylus longidactylus n. sp. is host specific (Geets et al., 1998). This study showed that monogenea was found in Pomatoschistus lozanoi from the North Sea (Geets et al., 1998) Longshaw et al. (2003) discovered that Gyrodactylus quadratidigitus n. sp. (Monogenea: Gyrodactylidae) was found on the on the gills and body surface of Thorogobius ephippiatus (Lowe). Neogobius fluviatilis, Neogobius kessleri and Neogobius melanostomus from Slovakia were investigated by OndraÄ kovà ¡ et al. (2003) and were found to be infected by a metazoan parasite.According to Garcia et al. (2004), Lepidogobius lepidus that has been newly recorded as being a host to thirty three cestode pleroceroides of Phyllobothrium sp. Digenea (Aphalloides timmi, Apatemon gracilis, Podocotyle atomon, Cryptocotyle concavum, Cryptocotyle lingua) and nematode (Hysterothylacium sp.) are found to be present externally and internally in Pomatoschistus minutus, P. pictus, P.microps, Gobiusculus flavescens and Gobius niger (Zander, 2004). Pampoulie et al. (1999) noted that infection of Aphalloà ¯des cÅ“lomicola has a bad impact on Pomatoschistus microps (Krà ¸yer, 1838). Gobies were described as main host and transmitters (Zander, 1993) of parasites. Zander (1998) noted that goby fishes serve the digenean, cestode, nematode and acanthoceplalan serve the goby fishes as their intermediate host. Pomatoschistus microps is the final host of Podocotyle atomon and Aphalloides timmi and these parasites had different abundance according to different seasons (Zander et al., 2002). Malek (2001) mentioned that Labratrema minimus and Cryptocotyle concavum have infected gobies (Pomatoschistus microps and Pomatoschistus minutes). According to Charlebois et al. (1997), there were 144 collected round gobies parasitized by 7 species of parasites. They are Diplostomum sp.(digenean), Eustrongylides tubifex(nematode), Rhabdochona decaturensis, Spinitectus sp., Spiroxys sp.(nematode), Leptorhyncchoides thecatus (class Palaeacanthocephala) and glochidia (larvae of freshwater bivalves). Apart from that, another study showed that four of the 67 gobies had parasites and three of them were infected by Acanthocephalus dirus while the latter was infected by nematode. Parasite infection of the male gobies was higher than female (Appleby, 1996). Most of the parasites were found from the gills, oral cavity and pharynx of gobies. Marianne et al. (2004) mentioned that Ellipsomyxa gobii (Myxozoa) infected goby, Pomatoschistus microps, as fish host. According to Lynda et al. (2004), there were four species of freshwater parasites were found in round goby, Neogobius melanostomus. These parasites included trematodes and crustaceans. Schistocephalus solidus, Aphalloides timmi and Apatemon gracilis including a metacecaria had been found in the goby fishes (Zander, 2001). These gobies have a low richness, prevelance, mean intensity and mean abundance of parasite. The gobies are intermediate host of digenean which is Diplostomum sp., acanthocephala (Acanthocephalus dirus) and nematode, Eustrongylides sp. (Camp et al., 1999). 1.6 Objectives of Study This is a general study on the parasites of oxudercine gobies (mudskippers) along the Selangor coastal area. The study is divided into two parts with the first part being a general survey of parasites on mudskippers while the second part discuss the relative factors affecting distribution of parasites. It also had an observation on the occurrences mudskippers along Selangor coast. Chapter 2 Materials and Methods 2.0 Introduction The present study focuses on the mudskippers found along the coastal area of Selangor. The fishes were caught from Jeram, Sementa (2 sites), Carey Island (3 sites) and Morib. A total of 127 specimens belonging to 7 species of mudskippers were collected and they included Boleophthalmus boddarti, Periophthalmus chrysospilos, Periophthalmus novemradiatus, Periophthalmus modestus, Periophthalmodon schlosseri, Pseudapocryptes elongates (Pseudapocryptes lanceolatus) and Scartelaos histophorus. Fish parts including the body surface, gills and gut were observed. The weight and the size of each specimen (standard size and the length) were recorded. Apart from that, the diet of mudskippers also was documented according to their stomach contents. Next, the parasites found from different parts of fish specimens were identified and tabulated. ANOVA, Coefficient of Dispersion, the Chi Square Test and population parameters were used to analyze data. 2.1 Methodology i) Fish collection site The fish specimens were caught by having the sampling at Jeram, Sementa, Carey Island and Morib (see 4). The field works were carried out during spring tide because the low tide was the lowest level while the high tide had the highest point when compared to the normal time. The salinity and pH of water were recorded. Fishes were caught by using different sizes of scoop net (medium or small). Otherwise, the fish can be caught using the cast net or by angling. Some crustaceans or small fishes were used as bait to attract fishes. The mudskippers were kept in water-filled aquarium to make sure that they may survive longer. (If the fishes die during sampling, some ice cubes can be added into plastic bag to freeze the dead fish). Species identification was done using a taxonomic characteristic key. 2.2 Fish Dissection Each fish was killed by a blow on their head or by severing the nerve cord. The weight and the size of specimen (standard size and the length) were recorded. After that, the gill and alimentary system of the fish were taken out step by step for observations. The parts examined were placed in a petri dish (with some drops of seawater in it. The seawater possibly contained the protozoans, copepods, mud, sea grasses and the others) Gill removal The operculum (a bony plate) was lifted and the gill parts were examined. Next, the operculum was cut across its base and the gill was being exposed. The gills were removed by cutting the upper and lower attachments of the arch. The gill apparatus were separated one by one into 8 pieces and the isolated gills were placed into a petri dish partially-filled with water. A pipette was used to suck and separate the parasite from the mucus, blood blot or tissues. A needle or a pair of fine forceps was usually used to scrape the mucus or tissue so as to separate the parasites from mucus or tissue. Alimentary system or gut part removal The alimentary system is a canal which starts from the esophagus and ends below the rectum. The body of the fish was cut longitudinally from the operculum parts till the tail part of the fish. After getting out the gill apparatus, it was lifted out together with the alimentary system by using a pair of forceps. The alimentary tract was cut into 4 parts (stomach, small intestine, big intestine and rectum). Again, a needle or forceps was used to scrape the mucus or tissue to separate the parasites from the mucus or tissue. The food items from the stomach content of the fish were recorded because this could possibly gives us some informations on the life cycle of parasite (Mhaisen and Al-Maliki, 1996) 2.3 Parasite collection Scalpel or dissecting needles were used to scrape gently the gill filaments and gut dermis of the fish. The parasite were sucked out by using a small pipette (if they were too small) or a pair of forceps (if they were bigger) and placed into a cavity block filled with some drops of seawater. Then, the parasite was examined under a dissecting microscope. The parasite was preserved using different methods according to the species of parasites. i) Fixation of the monogenean or any unknown species of parasite A coverslip was placed over the parasite after it was placed at the centre part of a slide. The slide-fixed parasite would be examined with a dissecting microscope to make sure the slide contained the specimen. After leaving the slide to be dry for a few minutes, a clear nail varnish was used to fix the four edges of the coverslip on the slide to prevent any movement of the coverslip. Ammonium picrate glycerin was added to the sides of the coverslip to allow it to seep under the coverslip, to fix and to clear the specimens. ii) Preservation methods for different types of parasite There were different parasite preservation methods used depending on the species and quantity of the collected parasites (see Table 1) Table 1: Preparation methods for different types of parasite Parasite Preparation methods Nematode Warm 70% alcohol was poured over the worms and later the specimens were transferred to fresh 70% alcohol for storage Trematode Digenea Warm 10% formalin was poured over the worms and the specimens were kept overnight in the fixative. They were transferred into fresh 70% alcohol for storage Cestode Warm 70% alcohol was poured over the worms and later transferred to fresh 70% alcohol for storage 2.4 Data analysis Coefficient of Dispersion (C.D) The coefficient of dispersion (C.D) was calculated to see how the population is dispersed, such as random, uniformed or clumped. It is calculated by dividing the variance over the mean and the relative relationship between mean and variance would establish the distribution pattern of the parasites in a population. If the C.D is close to or equals to one, the population is randomly dispersed. If the C.D is more than one, the population is clumped or over-dispersed. If the C.D is less than one, it shows that the population is uniformly dispersed or under-dispersed. The ratio of the mean to the variance is called the Coefficient of Dispersion (C.D) and the calculated formula is as below: The Analysis of Variance (ANOVA) The Analysis of Variance (ANOVA) (refer to Appendix A4) was used to test for significant differences among the variances. In this study, ANOVA was used to test for significant differences among the variances of parasites in the mudskippers sampled around the Selangor coastal area. In addition, the relative test had exhibited the interaction among the different factors affecting the occurrences and quantity of parasites. A test was calculated to show the correlation between the interaction of the different independent variables and the quantity of parasites on the gills and gut of the mudskipper. The significant result for fish survival in relation to the quantity of different parasite species under different variables was also documented. Chi Square Test The Chi Square Test was done to test whether a sample from a population follows a specified distribution or not. The Chi Square value was calculated as follow: Where as: = The observed number of cases which be written off as i row number of j column number = The expected number of cases which under the H0 to be characterized with i row number of j column number = It is run over all cells r = The number of rows in Chi-square table k = The number of columns in Chi-square table The calculated value was tested at a significance level of 95%. The value was yielded by the formula which was approximated by distribution with (r-1) (c-1). If the calculated value exceeded the tabulated one, the null hypothesis would be rejected at p = 0.05. Population Parameter The basic parasitological parameters which are prevalence, abundance and intensity were calculated for each parasite. According to Cox (1982), prevalence is defined by the percentage of host. Formula calculation of each basic parasitological parameter is as below: Prevalence is to look at how common a host (mudskipper) is infected in a population. Prevalence = Number of infected host X 100% Number of host examined Intensity is the quantity of parasite found in the host samples (mudskippers). Intensity = Total number of parasites Total number of infected host Abundance is the total number of parasites found in all the examined hosts. Abundance = Intensity Total number of host examined Chapter 3 Results and Discussions 3.0 Introduction This study focuses on parasites of oxudercine gobies (mudskippers) along Selangor coast. The fishes were caught (see Chapter 2) from Jeram, Sementa (2 sites), Carey Island (3 sites) and Morib (refer to 4). There were totally 127 mudskippers caught for study. The collected fish were identified by using taxonomic keys and cladistic analysis of family Gobiidae. 127 mudskippers consist of 7 species from 5 genera were collected. They were 27 Boleophthalmus boddarti, 36 Periophthalmus chrysospilos, 54 Periophthalmus novemradiatus, 1 Periophthalmus modestus, 1 Periophthalmodon schlosseri, 7 Pseudapocryptes elongates (Pseudapocryptes lanceolatus) and 1 Scartelaos histophorus (refer Appendix A3). In this study, parasites of the gills, the gut and the body surface of fish were investigated (see Chapter 2). There was found nothing from the body surface of fish. Five groups of parasites found from the whole study. They were monogenean, digenean, nematode, cestode and some unknown parasite cysts. Apart from that, the environmental factors (pH and salinity of water) also were discussed (see Table 2; Appendix A2). 3.1 Parasites of oxudercine gobies (mudskippers) Table 2 showed the summarized parasite data of oxudercine gobies (mudskippers) (refer to Appendix A2). Parasites species differ among oxudercine gobies (mudskippers) based on studied sites. Five groups of parasites were detected from this present study (see Table 3; 5-11). Identification is not easily to be done based on general main beliefs about parasite. There are varies in morphology and biological characters among parasites (see Satyu Yamaguti, 1953). The collected parasite consists of digeneans (see section 1.2; 5-8), monogenean (see section 1.2; 9), nematode (see section 1.2), cestode (see section 1.2; 10), and unidentified parasite cysts (see 11). Digeneans inhabit the gills and the gut of mudskippers (see Table 3). In this study, three types of digeneans were found in the gut of mudskippers. However, two of these three types of digeneans were also found in the gills. These digeneans are probably regurgitated from the gut as they have the same morphology with the guts digeneans. Gyrodactylus sp. (Monogenea, Gyrodactylidae) was described from the gills of mudskippers (see 8). The gills are the preferred part for monogenean. Table 3 showed that cestode and nematode inhabit the gut of fish specimens. Most of them found as encysted form in the mudskippers. In this study, the unidentified parasites cysts were found in the gills and gut of the mudskippers (see Table 3; 11). The unidentified parasites found in the gut of the mudskippers are probably cysts of cestode or nematode. However, some unknown parasites cysts which were found in the gills are considered as myxosporid. Table 2 Excel Table 3: Parasite record of the examined fish Parasite species Number of Species Microhabitat i) Digenea (see 5-8) 3 Gut and gill ii) Monogenea (see 9) 1 Gill iii) Cestode (see 10) 1 Gut iv) Nematode 1 Gut v)Unidentified parasite cysts 3.2 Parasites and their hosts Table 4 showed the presences of parasites on oxudercine gobies (mudskippers). Eight monogeneans were found limited to Pseudapocryptes lanceolatus (see Table 4 Table 5). Monogenean seems to be host specific and it prefers to inhabit the gills of Pseudapocryptes lanceolatus. Next, digeneans occurred in Periophthalmus chrysospilos and Periophthalmus novemradiatus (see table 4). There were 136 digeneans found in Periophthalmus chrysospilos while ten digeneans were detected from Periophthalmus novemradiatus (see Table 5). It is possibly because digeneans are able to adapt well in Periophthalmus chrysospilos. Periophthalmus chrysospilos, Periophthalmus novemradiatus and Periophthalmodon schlosseri were infected by cestodes (see Table 4). Most (twenty eight cestodes) were found in Periophthalmus novemradiatus (see Table 5). According to Table 5, there were twenty five nematodes found from Periophthalmus novemradiatus. Nematodes also occurred in Periophthalmodon schlosseri, mostly in the encysted form in the gut of mudskippers. There were 402 unidentified parasite cysts (see section 3.1) observed in Boleophthalmus boddarti, Periophthalmus modestus and Periophthalmus novemradiatus (see Table 4 Table 5). Most were found in Boleophthalmus boddarti. . Table 4: Parasites from Different Mudskippers Species Parasite Species Boleophthalmus boddarti Periophthalmus modestus Periophthalmus novemradiatus Host Species Periophthalmus chrysospilos Periophthalmodon schlosseri Pseudapocryptes Lanceolatus Scartelaos hisphorous Monogenea + Digenea + + Cestode + + Nematode + + + Unknown parasite cysts + + + = Parasite detected; = Parasite not detected Table 5: The Quantity of Compound Parasite Community Present in the Different Mudskipper Species Host Species Parasites Digenea Monogenea Nematode Cestode Unidentified cysts Boleophthalmus boddarti 0 0 0 0 395 Periophthalmus chrysospilos 136 0 0 1 0 Periophthalmus novemradiatus 10 0 7 28 6 Periophthalmus modestus 0 0 0 0 1 Pseudopocryptes lanceolatus 0 8 0 0 0 Periophthalmodon schlosseri 0 0 25 4 0 Scartelaos histophorus 0 0 0 0 0 3.3 Parasite and their habitat The salinity and pH of the water from the specimen collection areas were recorded (see table 2). Table 6 showed that site Sementa 2 with salinity reading from 23†° to 25†° and pH of water between 7.35 and 7.58 had the highest parasitic infection rate. There were 29 out of 40 samples found to have parasitic infection. Morib recorded the lowest parasitic infection rate (6%), only one out of 18 mudskippers was infected with parasite cysts. The parasitic infection rate of the mudskippers may perhaps vary with a distinct study area. The abundance of parasite was probably affected by the salinity of the macro-habitat (Zander Reimer, 2002). Monogenean prefers to inhabit in water with pH 7.44 (see Table 7; 13). Digeneans can be found in water with pH ranging from 5.71 to 8.71 (Table 7). Most digeneans were found in water with pH 7.35. Cestode and nematode occurred individually in the inner body of the host. Cestodes were found from the site Carey Island 2, site Sementa 2 and Morib (see Table 2). Table 7 showed that twenty-eight cestodes were found from site Carey Island 2 (see Table 2) with water pH measured as 5.71. Nematodes could be found in water with a wide range of pH ranging from 5.71 to 8.71 (Table 7). With reference to Table 7, the unidentified parasite cysts were found more abundantly in water pH 7.35 (Table 7; 14). The abundance of parasites in a distinct area differs with pH of water based on their own optimum pH and tolerance to the environment. Table 6: The Parasitic Infection of Mudskipper in Different Locations along Selangor Coast Locations Total of Samples pH water(†°) Salinity Parasitic infections Infection Rate Jeram 5 N.A N.A 2 40% Carey Island 1 5 7.44 11 3 60% Carey Island 2 36 5.71 17 14 39% Carey Island 3 3 8.17 11 2 67% Sementa1 20 6.81 28 5 25% Sementa2 40 7.35-7.58 23-25 29 73% Morib 18 7.21 25-30 1 6% 2 Table 7 : Parasites in different pH range. pH of water Parasite 5.71 6.81 7.21 7.35 7.44 7.58 8.17 Digenea 10 0 1 135 0 0 1 Cestode Types of Parasites Types of Parasites Chapter 1 General Introduction 1.0 Introduction 1.1 Fish Parasites Parasitism is an obligatory association between two distinct species, in which one species parasite is dependent on its host for nutrients and shelter (Elmer Glenn, 1961). The parasites can be divided into two groups which are ectoparasites and endoparasites. Ectoparasites are found on the external surfaces of the host such as skin, fins and gills, while endoparasites usually hide within the internal tissues or organs in the host (Cheng, 1986). Fishes acts as hosts to a wide variety of parasites such as the protozoans, platyhelminthes, acanthocephalan, nematodes and crustaceans (Lim, 1987). Parasites are typically smaller than their host. A distinct host usually found to be infected by a group of parasites (Zander, 1998). The chemical and physical factors which are either in micro-environment or macro-environment play an important role to determine the distribution and density of parasites (Cheng, 1986). Parasites show a preference among different age groups (Zander et al., 1993), sex of host (Lim, 1987) or according to host density and behaviour (Cheng, 1986). Remarkably, parasites have a distinguished ability to deal with the normal physiological and structural changes of the host, for example, the peristaltic movement and intestinal mucosa (Cheng, 1986) for survival, and starting their parasitism phase. Apart from that, the presence of parasites commonly irritates the host, causing immunological change (Lim, 1979) and may eventually cause death (Zander, 1998). Parasites penetrate the hosts tissue, causing chronic body system problems to the host. Moreover, the irritation site will initiate secondary infection by micro-organisms to the host (Cheng, 1986). 1.2 Specific parasite Gobies play a role as main host and transmitters (Zander, 1993) of parasites. Varieties of protozoan, helminthes, mollusks, crustaceans have been described as parasites of fish (Lim, 1987). They are able to reproduce either sexually or asexually. Some species of parasites have specific attachment to enable them to hold onto the host for food, transport (Cheng, 1986) or shelter (Elmer Glenn, 1961). The phylum Platyhelminthes consists of a large group of free-living invertebrates but most live as parasitic species on or in other organisms. There are 3 main classes under this phylum, namely, class Monogenea, class Trematode, and class Cestoda (Solomon et al., 2002). Monogeneans are typical gillworms (Bunkley-Williams E. H. Williams, 1994). Some species attach themselves on the body surface or invade into the inner organ of aquatic species (Reed, Francis-Floyd Klinger, 1996). Monogeneans have a series of hooks that enable them to attach on the host (Reed et al., 1996). They usually inhabit the gill and feed on skin mucosa (Lim, 1987). Reed et al. (1996) mentioned that a monogenean, Dactylogyrus sp., usually attaches itself to the gills of freshwater fish. It reproduces by laying eggs, while Gyrodactylus is typically found on the skin and fins of fish. This parasite produces live young or can be described as viviparous during its whole life. Digenea was formerly described as digenetic trematodes and this species of flukes usually has at least two hosts in their life cycle (Smyth, 1962). The parasite usually has a terminal opening mouth with a sucker which is subterminal or ventral. It may or may not have an oral sucker (Yamagutti, 1958). They are particularly found as endoparasites in the digestive tract, but are sometimes found throughout the inner organ systems of vertebrates (Yamagutti, 1958). The adult digeneans are commonly hermaphroditic but reproduction still requires two worms. Digeneans have a complex life cycle with two to three intermediate hosts (Cheng, 1986). Cestode is a parasitic flatworm or commonly known as tapeworm (Solomon, et al., 2002). An adult worm consists of a scolex which maybe armed with suckers and sometimes hooks for attachment on host (Solomon et al., 2002); and a strobila which is a linear series that be formed by one or more segments (also described as proglottides) which contain reproductive structures (Yamagutti, 1959). Most of the cestodes are monoecious and each proglottid has a male reproductive system and a female reproductive system. Both self and cross-fertilization will take place in cestode (Smyth, 1962). Nematode is commonly called as round worm (Solomon et al., 2002) that can infect a vertebrates eye, mouth, alimentary system, body cavity and the other parts (Smyth, 1962). This species can also be found as a parasite of many species of fishes. Some species parasitize plants and are described as an important agricultural pest (Campbell, 2002). It is smooth and consists of a cylindrical body, a pointed tail and cuticle layer surrounding its body (Solomon et al., 2002). Nematodes are typically dioecious. The female is generally larger than the male (Cheng, 1986). Apart from that, nematode life cycles differ depending on the species of the nematode (Smyth, 1962). 1.3 The Family of Gobiidae The members which form the family Gobiidae are known as gobies. It is the largest family of marine fishes and consists of two hundred genera (retrieved from Wikipedia). The members of the Family Gobiidae have their own special characteristics. They have a cylindrical body and the pelvic fins usually form an adhesive disc (Maurice Anthony, 1993). This species usually inhabits the shore in shallow bays and estuaries and also freshwater swamps and lakes (retrieved from Wikipedia). Some species are restricted to coral reefs, rocky coast, sandy, mangrove swamp or muddy beaches (Murdy, 1989). 1.4 Oxudercine Gobies (Mudskippers) The mudskippers are known as ‘ikan belacak, ‘ikan tembakul or ‘ikan belukor in Malay. The members of the goby family classified as mudskipper species based on body traits and behaviours (Murdy, 1989). Oxudercine gobies are described as the members of mudskippers (Murdy, 1989). There are thirty four species from ten genera found throughout the world (Murdy, 1989). They are Apocryptes, Zappa, Pseudapocryptes, Apocryptodon, Parapocryptes, Oxuderces, Scartelaos, Boleophthalmus, Periophthalmodon and Periophthalmus. Only seven genera of mudskippers (Periopthalmodon, Periophthalmus, Boleophthalmus, Scartelaos, Oxuderces, Parapocryptes and Pseudopocryptes) were found along the Selangor coast (Khaironizam, 2004). According to Khaironizam (2004), Cantor (1849) had identified five species of mudskippers while Koumans (1953) had noted eight species in Malaysia. Apart from that, there were four species already reported by Macne (1968) and five species were described by Berry (1972). He also mentioned that Murdy (1989) stated 11 species of mudskippers in Malaysia while Takita (1999) had studied 12 species of mudskippers (refer to Appendix A5). The mudskippers are euryhaline and semi-terrestrial species (Clayton, 1993). They have a rounded body and united pelvic fins. They also have a pair of protruding eyes and one to two rows of teeth in the upper jaws. Besides this, they can survive for a long time above water and move on land. Commonly, the males are smaller than the females. The mudskippers usually feed on crabs, insects, and other small organisms (Clayton, 1993). There are several adaptations that allow the mudskippers to survive successfully out of the water. Their bronchial chamber can fill up with water which allows them to walk on land for up to several hours. They spend much of their lives out of water and are able to undergo osmoregulation as well as oxygen uptake via their skin and gills (Clayton, 1993). They are abundant in muddy areas or mangroves. Oxudercine gobies often build mud towers around their burrows as refuge from predators (Clayton, 1993). The mudskippers have certain economic importance which provide substituted fishery for the period of torrential rain in some coastal countries. These fishes are commonly eaten in China, Taiwan, India and some parts of Malaysia. Nowadays, the mudskippers are also used as feed for aquarium fish (Clayton, 1993) 1.4.1 World Distribution of Mudskippers Mudskippers can be found around the tropical world as well as in the coastal regions of Asia, from Indonesia to Borneo (see 3). A few species are also found in Africa and Australia, whereas none are found in the new world (refer to Appendix A1). 1.5 Literature Reviews on Gobiid Parasites (refer to Appendix A7) There is too few research on parasitological studies of mudskipper in the Asian region. Most of the studies nowadays concentrate on the behavior and ecology of oxudercinae gobies (Khaironizam, 2004); taxonomic and cladistic of the oxudercine gobies (Murdy, 1989); and the nitrogen excretion of mudskipper in water and on land, the growth of mudskipper, habitat of mudskipper and osmoregulation system among this species (Clayton, 1993). Mhaisen and Al-Maliki (1996) mentioned that Myxobolus pfeifferi (Sporozoa), Diplozoon sp. (Monogenea) and Neoechinorhynchus sp. (Acanthocephala) were found in dark-blotched mudskippers, Periophthalmus waltoni, from the mudflats of the Khor Al-Zubair estuary. A new record showed the heterophyid (trematode) had served Boleophthalmus pectinirostris and Scartelaos sp. as second intermediate host (Sohn et al., 2005). Clayton (1993) indicated that cestode, agamofilarial and acanthocephalid cysts have been described as parasite in Periophthalmus koelreuteri (Pearse, 1933), Periphthalmodon schlosseri and Boleophthalmus boddarti (Khoo, 1966). Besides, the larval ascarid nematodes infected Periophthalmodon schlosseri (Khoo, 1966). Pseudapocryptes lanceolatus were found to be infected by parasitic copepod, Gnathia sp. A larval cestode was also described by Pearse (1932) in Periophthalmus modestus. A study by Choudhury and Nandi (1973) did not establish any parasitic infection on Boleophthalmus boddarti and Scartelaos histophorus. The intestinal flagellates were also noted by Pearse (1933) in Boleophthamus boddarti. The bacterial flora had been observed by Morii and Kasama (1989) to be in the intestine of Boleophthalmus pectinirostris and Periophthalmus modestus. In West Africa and Singapore, a new species of acanthocephalan was detected in Periophthalmus barbarus and Periophthalmus schlosseri. Eighteen Gyrodactylus species were collected from gobies of the genus Pomatoschistus and the host-parasite relationship was discussed (Huyse et al., 2003). Geets et al. (1999) found that three gobies (Pomatoschistus minutus, P. lozanoi and P. pictus) were infected by Gyrodactylus arcuatus in the North Sea and noted that Gyrodactylus longidactylus n. sp. is host specific (Geets et al., 1998). This study showed that monogenea was found in Pomatoschistus lozanoi from the North Sea (Geets et al., 1998) Longshaw et al. (2003) discovered that Gyrodactylus quadratidigitus n. sp. (Monogenea: Gyrodactylidae) was found on the on the gills and body surface of Thorogobius ephippiatus (Lowe). Neogobius fluviatilis, Neogobius kessleri and Neogobius melanostomus from Slovakia were investigated by OndraÄ kovà ¡ et al. (2003) and were found to be infected by a metazoan parasite.According to Garcia et al. (2004), Lepidogobius lepidus that has been newly recorded as being a host to thirty three cestode pleroceroides of Phyllobothrium sp. Digenea (Aphalloides timmi, Apatemon gracilis, Podocotyle atomon, Cryptocotyle concavum, Cryptocotyle lingua) and nematode (Hysterothylacium sp.) are found to be present externally and internally in Pomatoschistus minutus, P. pictus, P.microps, Gobiusculus flavescens and Gobius niger (Zander, 2004). Pampoulie et al. (1999) noted that infection of Aphalloà ¯des cÅ“lomicola has a bad impact on Pomatoschistus microps (Krà ¸yer, 1838). Gobies were described as main host and transmitters (Zander, 1993) of parasites. Zander (1998) noted that goby fishes serve the digenean, cestode, nematode and acanthoceplalan serve the goby fishes as their intermediate host. Pomatoschistus microps is the final host of Podocotyle atomon and Aphalloides timmi and these parasites had different abundance according to different seasons (Zander et al., 2002). Malek (2001) mentioned that Labratrema minimus and Cryptocotyle concavum have infected gobies (Pomatoschistus microps and Pomatoschistus minutes). According to Charlebois et al. (1997), there were 144 collected round gobies parasitized by 7 species of parasites. They are Diplostomum sp.(digenean), Eustrongylides tubifex(nematode), Rhabdochona decaturensis, Spinitectus sp., Spiroxys sp.(nematode), Leptorhyncchoides thecatus (class Palaeacanthocephala) and glochidia (larvae of freshwater bivalves). Apart from that, another study showed that four of the 67 gobies had parasites and three of them were infected by Acanthocephalus dirus while the latter was infected by nematode. Parasite infection of the male gobies was higher than female (Appleby, 1996). Most of the parasites were found from the gills, oral cavity and pharynx of gobies. Marianne et al. (2004) mentioned that Ellipsomyxa gobii (Myxozoa) infected goby, Pomatoschistus microps, as fish host. According to Lynda et al. (2004), there were four species of freshwater parasites were found in round goby, Neogobius melanostomus. These parasites included trematodes and crustaceans. Schistocephalus solidus, Aphalloides timmi and Apatemon gracilis including a metacecaria had been found in the goby fishes (Zander, 2001). These gobies have a low richness, prevelance, mean intensity and mean abundance of parasite. The gobies are intermediate host of digenean which is Diplostomum sp., acanthocephala (Acanthocephalus dirus) and nematode, Eustrongylides sp. (Camp et al., 1999). 1.6 Objectives of Study This is a general study on the parasites of oxudercine gobies (mudskippers) along the Selangor coastal area. The study is divided into two parts with the first part being a general survey of parasites on mudskippers while the second part discuss the relative factors affecting distribution of parasites. It also had an observation on the occurrences mudskippers along Selangor coast. Chapter 2 Materials and Methods 2.0 Introduction The present study focuses on the mudskippers found along the coastal area of Selangor. The fishes were caught from Jeram, Sementa (2 sites), Carey Island (3 sites) and Morib. A total of 127 specimens belonging to 7 species of mudskippers were collected and they included Boleophthalmus boddarti, Periophthalmus chrysospilos, Periophthalmus novemradiatus, Periophthalmus modestus, Periophthalmodon schlosseri, Pseudapocryptes elongates (Pseudapocryptes lanceolatus) and Scartelaos histophorus. Fish parts including the body surface, gills and gut were observed. The weight and the size of each specimen (standard size and the length) were recorded. Apart from that, the diet of mudskippers also was documented according to their stomach contents. Next, the parasites found from different parts of fish specimens were identified and tabulated. ANOVA, Coefficient of Dispersion, the Chi Square Test and population parameters were used to analyze data. 2.1 Methodology i) Fish collection site The fish specimens were caught by having the sampling at Jeram, Sementa, Carey Island and Morib (see 4). The field works were carried out during spring tide because the low tide was the lowest level while the high tide had the highest point when compared to the normal time. The salinity and pH of water were recorded. Fishes were caught by using different sizes of scoop net (medium or small). Otherwise, the fish can be caught using the cast net or by angling. Some crustaceans or small fishes were used as bait to attract fishes. The mudskippers were kept in water-filled aquarium to make sure that they may survive longer. (If the fishes die during sampling, some ice cubes can be added into plastic bag to freeze the dead fish). Species identification was done using a taxonomic characteristic key. 2.2 Fish Dissection Each fish was killed by a blow on their head or by severing the nerve cord. The weight and the size of specimen (standard size and the length) were recorded. After that, the gill and alimentary system of the fish were taken out step by step for observations. The parts examined were placed in a petri dish (with some drops of seawater in it. The seawater possibly contained the protozoans, copepods, mud, sea grasses and the others) Gill removal The operculum (a bony plate) was lifted and the gill parts were examined. Next, the operculum was cut across its base and the gill was being exposed. The gills were removed by cutting the upper and lower attachments of the arch. The gill apparatus were separated one by one into 8 pieces and the isolated gills were placed into a petri dish partially-filled with water. A pipette was used to suck and separate the parasite from the mucus, blood blot or tissues. A needle or a pair of fine forceps was usually used to scrape the mucus or tissue so as to separate the parasites from mucus or tissue. Alimentary system or gut part removal The alimentary system is a canal which starts from the esophagus and ends below the rectum. The body of the fish was cut longitudinally from the operculum parts till the tail part of the fish. After getting out the gill apparatus, it was lifted out together with the alimentary system by using a pair of forceps. The alimentary tract was cut into 4 parts (stomach, small intestine, big intestine and rectum). Again, a needle or forceps was used to scrape the mucus or tissue to separate the parasites from the mucus or tissue. The food items from the stomach content of the fish were recorded because this could possibly gives us some informations on the life cycle of parasite (Mhaisen and Al-Maliki, 1996) 2.3 Parasite collection Scalpel or dissecting needles were used to scrape gently the gill filaments and gut dermis of the fish. The parasite were sucked out by using a small pipette (if they were too small) or a pair of forceps (if they were bigger) and placed into a cavity block filled with some drops of seawater. Then, the parasite was examined under a dissecting microscope. The parasite was preserved using different methods according to the species of parasites. i) Fixation of the monogenean or any unknown species of parasite A coverslip was placed over the parasite after it was placed at the centre part of a slide. The slide-fixed parasite would be examined with a dissecting microscope to make sure the slide contained the specimen. After leaving the slide to be dry for a few minutes, a clear nail varnish was used to fix the four edges of the coverslip on the slide to prevent any movement of the coverslip. Ammonium picrate glycerin was added to the sides of the coverslip to allow it to seep under the coverslip, to fix and to clear the specimens. ii) Preservation methods for different types of parasite There were different parasite preservation methods used depending on the species and quantity of the collected parasites (see Table 1) Table 1: Preparation methods for different types of parasite Parasite Preparation methods Nematode Warm 70% alcohol was poured over the worms and later the specimens were transferred to fresh 70% alcohol for storage Trematode Digenea Warm 10% formalin was poured over the worms and the specimens were kept overnight in the fixative. They were transferred into fresh 70% alcohol for storage Cestode Warm 70% alcohol was poured over the worms and later transferred to fresh 70% alcohol for storage 2.4 Data analysis Coefficient of Dispersion (C.D) The coefficient of dispersion (C.D) was calculated to see how the population is dispersed, such as random, uniformed or clumped. It is calculated by dividing the variance over the mean and the relative relationship between mean and variance would establish the distribution pattern of the parasites in a population. If the C.D is close to or equals to one, the population is randomly dispersed. If the C.D is more than one, the population is clumped or over-dispersed. If the C.D is less than one, it shows that the population is uniformly dispersed or under-dispersed. The ratio of the mean to the variance is called the Coefficient of Dispersion (C.D) and the calculated formula is as below: The Analysis of Variance (ANOVA) The Analysis of Variance (ANOVA) (refer to Appendix A4) was used to test for significant differences among the variances. In this study, ANOVA was used to test for significant differences among the variances of parasites in the mudskippers sampled around the Selangor coastal area. In addition, the relative test had exhibited the interaction among the different factors affecting the occurrences and quantity of parasites. A test was calculated to show the correlation between the interaction of the different independent variables and the quantity of parasites on the gills and gut of the mudskipper. The significant result for fish survival in relation to the quantity of different parasite species under different variables was also documented. Chi Square Test The Chi Square Test was done to test whether a sample from a population follows a specified distribution or not. The Chi Square value was calculated as follow: Where as: = The observed number of cases which be written off as i row number of j column number = The expected number of cases which under the H0 to be characterized with i row number of j column number = It is run over all cells r = The number of rows in Chi-square table k = The number of columns in Chi-square table The calculated value was tested at a significance level of 95%. The value was yielded by the formula which was approximated by distribution with (r-1) (c-1). If the calculated value exceeded the tabulated one, the null hypothesis would be rejected at p = 0.05. Population Parameter The basic parasitological parameters which are prevalence, abundance and intensity were calculated for each parasite. According to Cox (1982), prevalence is defined by the percentage of host. Formula calculation of each basic parasitological parameter is as below: Prevalence is to look at how common a host (mudskipper) is infected in a population. Prevalence = Number of infected host X 100% Number of host examined Intensity is the quantity of parasite found in the host samples (mudskippers). Intensity = Total number of parasites Total number of infected host Abundance is the total number of parasites found in all the examined hosts. Abundance = Intensity Total number of host examined Chapter 3 Results and Discussions 3.0 Introduction This study focuses on parasites of oxudercine gobies (mudskippers) along Selangor coast. The fishes were caught (see Chapter 2) from Jeram, Sementa (2 sites), Carey Island (3 sites) and Morib (refer to 4). There were totally 127 mudskippers caught for study. The collected fish were identified by using taxonomic keys and cladistic analysis of family Gobiidae. 127 mudskippers consist of 7 species from 5 genera were collected. They were 27 Boleophthalmus boddarti, 36 Periophthalmus chrysospilos, 54 Periophthalmus novemradiatus, 1 Periophthalmus modestus, 1 Periophthalmodon schlosseri, 7 Pseudapocryptes elongates (Pseudapocryptes lanceolatus) and 1 Scartelaos histophorus (refer Appendix A3). In this study, parasites of the gills, the gut and the body surface of fish were investigated (see Chapter 2). There was found nothing from the body surface of fish. Five groups of parasites found from the whole study. They were monogenean, digenean, nematode, cestode and some unknown parasite cysts. Apart from that, the environmental factors (pH and salinity of water) also were discussed (see Table 2; Appendix A2). 3.1 Parasites of oxudercine gobies (mudskippers) Table 2 showed the summarized parasite data of oxudercine gobies (mudskippers) (refer to Appendix A2). Parasites species differ among oxudercine gobies (mudskippers) based on studied sites. Five groups of parasites were detected from this present study (see Table 3; 5-11). Identification is not easily to be done based on general main beliefs about parasite. There are varies in morphology and biological characters among parasites (see Satyu Yamaguti, 1953). The collected parasite consists of digeneans (see section 1.2; 5-8), monogenean (see section 1.2; 9), nematode (see section 1.2), cestode (see section 1.2; 10), and unidentified parasite cysts (see 11). Digeneans inhabit the gills and the gut of mudskippers (see Table 3). In this study, three types of digeneans were found in the gut of mudskippers. However, two of these three types of digeneans were also found in the gills. These digeneans are probably regurgitated from the gut as they have the same morphology with the guts digeneans. Gyrodactylus sp. (Monogenea, Gyrodactylidae) was described from the gills of mudskippers (see 8). The gills are the preferred part for monogenean. Table 3 showed that cestode and nematode inhabit the gut of fish specimens. Most of them found as encysted form in the mudskippers. In this study, the unidentified parasites cysts were found in the gills and gut of the mudskippers (see Table 3; 11). The unidentified parasites found in the gut of the mudskippers are probably cysts of cestode or nematode. However, some unknown parasites cysts which were found in the gills are considered as myxosporid. Table 2 Excel Table 3: Parasite record of the examined fish Parasite species Number of Species Microhabitat i) Digenea (see 5-8) 3 Gut and gill ii) Monogenea (see 9) 1 Gill iii) Cestode (see 10) 1 Gut iv) Nematode 1 Gut v)Unidentified parasite cysts 3.2 Parasites and their hosts Table 4 showed the presences of parasites on oxudercine gobies (mudskippers). Eight monogeneans were found limited to Pseudapocryptes lanceolatus (see Table 4 Table 5). Monogenean seems to be host specific and it prefers to inhabit the gills of Pseudapocryptes lanceolatus. Next, digeneans occurred in Periophthalmus chrysospilos and Periophthalmus novemradiatus (see table 4). There were 136 digeneans found in Periophthalmus chrysospilos while ten digeneans were detected from Periophthalmus novemradiatus (see Table 5). It is possibly because digeneans are able to adapt well in Periophthalmus chrysospilos. Periophthalmus chrysospilos, Periophthalmus novemradiatus and Periophthalmodon schlosseri were infected by cestodes (see Table 4). Most (twenty eight cestodes) were found in Periophthalmus novemradiatus (see Table 5). According to Table 5, there were twenty five nematodes found from Periophthalmus novemradiatus. Nematodes also occurred in Periophthalmodon schlosseri, mostly in the encysted form in the gut of mudskippers. There were 402 unidentified parasite cysts (see section 3.1) observed in Boleophthalmus boddarti, Periophthalmus modestus and Periophthalmus novemradiatus (see Table 4 Table 5). Most were found in Boleophthalmus boddarti. . Table 4: Parasites from Different Mudskippers Species Parasite Species Boleophthalmus boddarti Periophthalmus modestus Periophthalmus novemradiatus Host Species Periophthalmus chrysospilos Periophthalmodon schlosseri Pseudapocryptes Lanceolatus Scartelaos hisphorous Monogenea + Digenea + + Cestode + + Nematode + + + Unknown parasite cysts + + + = Parasite detected; = Parasite not detected Table 5: The Quantity of Compound Parasite Community Present in the Different Mudskipper Species Host Species Parasites Digenea Monogenea Nematode Cestode Unidentified cysts Boleophthalmus boddarti 0 0 0 0 395 Periophthalmus chrysospilos 136 0 0 1 0 Periophthalmus novemradiatus 10 0 7 28 6 Periophthalmus modestus 0 0 0 0 1 Pseudopocryptes lanceolatus 0 8 0 0 0 Periophthalmodon schlosseri 0 0 25 4 0 Scartelaos histophorus 0 0 0 0 0 3.3 Parasite and their habitat The salinity and pH of the water from the specimen collection areas were recorded (see table 2). Table 6 showed that site Sementa 2 with salinity reading from 23†° to 25†° and pH of water between 7.35 and 7.58 had the highest parasitic infection rate. There were 29 out of 40 samples found to have parasitic infection. Morib recorded the lowest parasitic infection rate (6%), only one out of 18 mudskippers was infected with parasite cysts. The parasitic infection rate of the mudskippers may perhaps vary with a distinct study area. The abundance of parasite was probably affected by the salinity of the macro-habitat (Zander Reimer, 2002). Monogenean prefers to inhabit in water with pH 7.44 (see Table 7; 13). Digeneans can be found in water with pH ranging from 5.71 to 8.71 (Table 7). Most digeneans were found in water with pH 7.35. Cestode and nematode occurred individually in the inner body of the host. Cestodes were found from the site Carey Island 2, site Sementa 2 and Morib (see Table 2). Table 7 showed that twenty-eight cestodes were found from site Carey Island 2 (see Table 2) with water pH measured as 5.71. Nematodes could be found in water with a wide range of pH ranging from 5.71 to 8.71 (Table 7). With reference to Table 7, the unidentified parasite cysts were found more abundantly in water pH 7.35 (Table 7; 14). The abundance of parasites in a distinct area differs with pH of water based on their own optimum pH and tolerance to the environment. Table 6: The Parasitic Infection of Mudskipper in Different Locations along Selangor Coast Locations Total of Samples pH water(†°) Salinity Parasitic infections Infection Rate Jeram 5 N.A N.A 2 40% Carey Island 1 5 7.44 11 3 60% Carey Island 2 36 5.71 17 14 39% Carey Island 3 3 8.17 11 2 67% Sementa1 20 6.81 28 5 25% Sementa2 40 7.35-7.58 23-25 29 73% Morib 18 7.21 25-30 1 6% 2 Table 7 : Parasites in different pH range. pH of water Parasite 5.71 6.81 7.21 7.35 7.44 7.58 8.17 Digenea 10 0 1 135 0 0 1 Cestode