A study had been carried out to determine Cu, Zn, Cd, Hg and Pb concentrations in the muscle and fins of four elasmobranchs species namely spot-tail sharks, milk sharks, whitespotted bamboo sharks and whitespotted guitarfish from Pulau Kambing LKIM Fishery Complex, Kuala Terengganu, Malaysia. Zinc level was found to have the highest concentration whereas Cd had the lowest concentration in both organs. By comparing both organs, metals concentrations in fins of all elasmobranchs species were higher than muscle. Result obtained was compared with the guidelines set by Malaysian Food Regulation and the provisional tolerable weekly intake was also determined. Current study recommends that the muscle of whitespotted bamboo shark from Kuala Terengganu Waters is likely not to be consumed due to it exceeded the allowable consumption guideline. Finding of this paper is very useful as it provides the baseline data on the pollution status of elasmobranchs in Kuala Terengganu Waters.
Analyses of conventional morphometric, meristic and truss morphometric were performed on two
species of Pangasiid catfish, Pangasius pangasius and P. nasutus. The purpose is to find characters that help in differentiating these two species to avoid confusion among fish farmers. Three morphometric approaches (conventional, meristic and truss morphometric) were employed to identify the morphological differences. Conventional morphometric suggested eye diameter, body width, body depth, dorsal fin base length and barbells as characters that have significant differences (P< 0.05) between the species, hence making them as potential diagnostic markers. Truss morphometric analyses approved that P. nasutus have larger dorsal fin base length as suggested by conventional morphometry data. Meristic analysis showed significant difference (P
The caligid parasite Caligus coryphaenae has been reported in several marine fishes from Japan. In this study, a total of 223 wild yellowtail (Seriola quinqueradiata) were collected from Kagoshima fish market, separated into three groups according to total length (TL 70 cm), and examined for C. coryphaenae infection. A total of 518 specimens of C. coryphaenae were isolated giving an overall prevalence of infection and mean intensity of 24.2% and 4.7 ± 3.5, respectively. Body surface, fins and operculum of hosts TL > 50 cm were recorded as preferred sites for the attachment of C. coryphaenae. Of female specimens, 56.7% bore egg strings with various egg string lengths (7.1 ± 1.2 mm), carrying from 98 to 140 eggs (0.06 ± 0.005 mm in length) per each string. To our knowledge, this is the first report of C. coryphaenae infection from wild yellowtail in Japanese waters and globally. This parasite has not been reported in yellowtail culture to date, but the finding on wild specimens of yellowtail means that it poses a risk to their culture.
Isopods occur very commonly as parasites in food fishes. Parasitic isopods are typically marine and usually inhabit the warmer seas. They are blood-feeding; several species settle in the buccal cavity of fish, others live in the gill chamber or on the body surface including the fins. Isopods can cause morbidity and mortality in captive fish populations. The infestation usually pressure atrophy often accompanies the presence of larger parasites. The present study was aimed at collecting information on the neglected group of isopod parasites of the marine fishes from the Miri coastal environment, East Malaysia. A very little information available regarding the distribution of isopod parasites of Malaysian coastal environment. In the present study, nine isopod parasites were oberved from ten marine fish species. The maximum number of parasites were observed in the months of June and October, 2013. Maximum prevalence was observed in October (50 %) and the minimum was observed in June (7.14 %). The parasitic infestation may lead to an economic loss in commercial fish species.
Lymphocystis disease (LCD) in fishes is caused by the agent called lymphocystis disease virus (LCDV). LCDV is a chronic and benign virus. The disease affects 96 species of marine and fresh water fishes ranged among 34 families in the world. Affected fish with LCD has a typical external symptom with clusters consisted of enormously hypertrophied dermal cells on the skin and fins. The hypertrophied cells, generally named lymphocystis cells, have a thick hyaline capsule, an enlarged nucleus and prominent basophilic cytoplasmic inclusions. Among the four species of fishes, olive flounder Paralichthys olivaceus, and rockfish Sebastes schlegeli were marine cultured fish, and gourami Trichogaster leeri and painted glassfish Channa baculis were freshwater ornamental fish. Although LCD causes low mortality, the disfigurement of infected fish can make them unsellable. Thus LCD has resulted in an important economic loss in the aquaculture industry. This study of histopathology may be adequate for a presumptive diagnosis of lymphocystis diseases both in marine and freshwater fish species.
A preliminary linkage map was constructed by applying backcross and testcross strategy using microsatellite (SSR) markers developed for Xiphophorus and Poecilia reticulata in ornamental fish, molly Poecilia sp. The linkage map having 18 SSR loci consisted of four linkage groups that spanned a map size of 516.1cM. Association between genotypes and phenotypes was tested in a random fashion and QTL for dorsal fin length was found to be linked to locus Msb069 on linkage group 2. Coincidentally, locus Msb069 was also reported as putative homologue primer pairs containing SSRs repeat motif which encoded hSMP-1, a sex determining locus. Dorsal fin length particularly in males of Poecilia latipinna is an important feature during courtship display. Therefore, we speculate that both dorsal fin length and putative hSMP-1 gene formed a close proximity to male sexual characteristics.
In Malaysia, Piper sarmentosum or 'kaduk' is commonly used in traditional medicines. However, its biological effects including in vivo embryonic toxicity and tissue regenerative properties are relatively unknown. The purpose of this study was to determine zebrafish (Danio rerio) embryo toxicities and caudal fin tissue regeneration in the presence of P. sarmentosum aqueous extracts. The phytochemical components and antioxidant activity of the extract were studied using GC-MS analysis and DPPH assay, respectively. Embryo toxicity tests involving survival, heartbeat, and morphological analyses were conducted to determine P. sarmentosum extract toxicity (0-60 µg/mL); concentrations of 0-400 µg/mL of the extract were used to study tissue regeneration in the zebrafish caudal fin. The extract contained several phytochemicals with antioxidant activity and exhibited DPPH scavenging activity (IC50 = 50.56 mg/mL). Embryo toxicity assays showed that a concentration of 60 μg/mL showed the highest rates of lethality regardless of exposure time. Slower embryogenesis was observed at 40 µg/mL, with non-viable embryos first detected at 50 µg/mL. Extracts showed significant differences (p