Chromium (IV) transfer to Amusium pleuronectes by LDPE microplastics: An experimental study.

An experiment was carried out to investigate the potential of virgin LDPE microplastics to transfer heavy metals. Desired shapes (fibres, fragments, and films) and sizes (< 5 mm) of virgin LDPE microplastics were immersed in a known concentration (30 µg/l) of chromium (IV). These Cr-coated microplastics were introduced into a culture tank containing edible scallops (Amusium pleuronectes). After the completion of the experiment (5 days), the sediments in the culture tank and edible tissues of A. pleuronectes were tested for the presence of Cr. In the sediments, a maximum concentration of 1.934 µg/g of Cr was accumulated at a rate of R2 = 0.979, while in the tissues, the maximum accumulation concentration was 0.733 µg/g of Cr at a rate of R2 = 0.807. Energy Dispersive X-ray Spectroscopy analysis also confirmed the presence of Cr (2.61 ± 0.44 mass % and 1.80 ± 0.30 atom%) in the tissues of A. pleuronectes, which was absent in the control tissues. The study showed that when exposed to contaminants such as heavy metals, LDPE microplastics can adhere and transfer them to biotic tissues. LDPE showed the potential to transfer adhered contaminants; however, the effects caused by these transferred contaminants on biota must be studied further. Risk assessment study showed that potential ecological risk of Cr is < 40 indicating low risk however, the combined effect of Cr and LDPE can compound its toxicity which needs to be studied further.

A new species of the congrid eel genus Conger (Anguilliformes: Congridae) from the southwest coast of India.

A new species of Conger eel is described from a single specimen (569 mm total length) collected off Kanyakumari, Southwest coast of India, Arabian Sea. The following characters distinguish the new species from other congeners: dorsal-fin origin behind the pectoral-fin tip; head larger, 18.5% TL; longer predorsal length 24.0% TL; relatively shorter trunk, uniserial teeth at the posterior end of vomerine patch; body blackish to dark brown; pectoral fin completely darker; cephalic pores rim whitish; SO pores 3; IO pores 6; pectoral rays 19; total vertebrae 141+. Genetic analysis of the mitochondrial COI gene revealed that the new species is closely related to Conger verreauxi Kaup, 1856 and Conger macrocephalus Kanazawa, 1958, with a genetic divergence of 5.7% and 5.9% respectively.

Morphological and molecular approaches revealed a new species of snapping shrimp genus Alpheus Fabricius, 1798 (Decapoda: Caridea: Alpheidae) from Lakshadweep Islands, India.

A new species of the alpheid genus Alpheus Fabricius, 1798, Alpheus sulcipalma sp. nov., is described and illustrated based on the specimens collected from the intertidal zone of Agatti Island, Lakshadweep, India at 0.5-1.0 m depth. This species belongs to the A. edwardsii group by absences of tooth in the orbital hoods and presence of compressed major chela with dorsal and ventral notches. Alpheus sulcipalma sp. nov. is morphologically closely related with A. pacificus Dana, 1852, absence of balaeniceps crests in the minor chela and absences of spine in the merus of major pereiopod of both sexes. However, the new species differs from A. pacificus in presence of strong and broad triangular groove on the dorsolateral and dorsomesial surface of the palm of major chela; length ratio and armature of fingers and palm of minor chela, carpus segments of second and third pereiopods and telson length. The results of phylogenetic analyses using partial sequences of mitochondrial COI gene data compared between A. sulcipalma sp. nov. with congener species which strongly support the description of new species with available limited sequences. The interspecific genetic divergences of the COI gene for A. sulcipalma sp. nov. and A. pacificus were observed higher in ranges (11.1-28.9%).

New record of Urocaridella antonbruunii (Bruce, 1967) from Southern India with taxonomic Keys of Urocaridella Borradaile, 1915 (Decapoda; Palaemonidae).

The cleaning rock pool shrimp commonly inhabit the shallow waters of reef and crevices regions at 0.5-3.0 m depth. Recent exploration conducted off the Gulf of Mannar and Agatti Island yielded the species, Urocaridella antonbruunii (Bruce, 1967) from the bottom curve of the coral boulder at a depth of 0.5-1.0 m. This is the new record for the Gulf of Mannar and Lakshadweep waters. Major distinguishing morphological characters of the congener's were described and illustrated. The molecular analysis confirmed the species occurrence in Indian waters followed the intraspecific and interspecific genetic divergences (16S gene) were estimated between 0.3-2.1% for within species and 6.4-11.2% for between species respectively. Additionally, we updated and provided the illustrative key characters for all members of the genus Urocaridella.

A new alpheid shrimp, Alpheus mannarensis sp. nov. (Crustacea; Decapoda; Alpheidae) from Gulf of Mannar, Southern India.

A new species of the genus Alpheus Fabricius, 1798, A. mannarensis sp. nov. is described and represented based on the materials collected from the shallow and rocky reefs, Gulf of Mannar (Thoothukudi waters), Southern India. This is the first report of Alpheus species from the Gulf of Mannar region. The new species is assigned to the Alpheus brevirostris group, and is distinguished from other species of this group by the combination of the following features: rostral ridge lower than orbital hood in lateral view and postrostral carina not extended to the middle of the carapace, palm of major chela with a transverse groove near the base of dactylus, the ultimate segment of the third maxilliped slender, fingers of minor chela of male slightly longer than palm, the first carpal segment of second pereiopods shorter than second segment, merus of third pereiopods slender and unarmed, dactylus of third pereiopods slender and subspatulate, and unique colour patterns of longitudinal light lines on the reddish body.

Urocaridella arabianensis n. sp., a new Palaemonid shrimp (Crustacea, Decapoda, Palaemonidae) from Lakshadweep Islands, India with taxonomic comparison on the genus Urocaridella Borradaile, 1915.

A new species of the genus Urocaridella Borradaile, 1915, Urocaridella arabianensis n. sp. is described and illustrated based on fifty-five specimens collected from the reef regions of Agatti Island, Lakshadweep, Arabian Sea. Urocaridella arabianensis n. sp. is morphologically close to U. pulchella Yokes Galil, 2006, reported from the Mediterranean Sea. However, the present specimen is clearly distinguished with its rostrum length, which is 1.7 to 2.1 times as long as carapace, 10 ventral rostral teeth, carpus of 1st pereopod is 2.5 times long as palm, carpus of 2nd pereopod is 1.8 times as long as palm, presence of a spine in latero-middle of the fourth and fifth abdomens and the sixth abdominal segment is 2.3 times long as the fifth segment. Partial segment of the mitochondrial COI, 16S rRNA and nuclear gene 18S rRNA and H3 indicates that the new species is sister to a clade comprising of U. pulchella, U. antonbruunii and U. degravei. The pair wise genetic distance of COI showed great distance with the closest congeneric species.

Two new records of hippolytoid shrimps, Lysmata hochi Baeza amp; Anker, 2008 (Decapoda: Lysmatidae) and Lysmata amboinensis (de Man, 1888) from Lakshadweep Islands, India with taxonomic notes.

The present study reports the new records of two species of the hippolytid shrimp genus Lysmata Risso, 1816 in the water off Lakshadweep Islands, India from the Arabian Sea, viz. Lysmata hochi Baeza Anker, 2008 and Lysmata amboinensis (De Man, 1888) with more taxonomic information. Moreover, L. hochi is the first distributional report from the Indian Ocean. It is morphologically similar to L. kuekenthali and differences are discussed. Colour pattern and morphological trait of L. amboinensis are very close to L. grabhami which also differs in the presence of anti-penultimate segment of 3rd maxilliped more than 2.0 times as long as penultimate segment and stylocerite does not reaching the distal end of the cornea. These specimens were obtained at a depth of 0.5-2 m from the intertidal region of Agatti Island. Additionally, we estimated pairwise genetic distances for these two species and congeneric species using cytochrome oxidase subunit I gene sequences where interspecific distances ranged from 11-25.8 %.

New record of Thor hainanensis Xu amp; Li, 2014 and taxonomical remarks on Lysmata ternatensis de Man, 1902 (Decapoda: Thoridae amp; Lysmatidae) from the Lakshadweep Islands, India.

The present study reports the new record of Thor hainanensis Xu Li, 2014, on the basis of material from Agatti Islands in the Lakshadweep, India. This species was recently described from Hainan Island, China. Relationship of this species to two closely related species (T. paschalis and T. amboinensis) is discussed in this manuscript. Similarly, the present study also reports the rediscovery of other species, Lysmata ternatensis De Man, 1902 from the Lakshadweep waters with detailed taxonomic description. The present specimens were found to occur in the intertidal region in small crevices and rocks at a depth of 0.5-2.0 m. Genetic analysis using the mitochondrial COI sequences for both the species reveals close agreement for the morphological identification and showed the significant variation from the closely related species.

Periclimenella agattii sp. nov., a new Palaemonid shrimp (Crustacea, Decapoda, Palaemonidae) from Lakshadweep Islands, India.

The recent collection of Palaemonid shrimps from Agatti Island, Lakshadweep, Arabian Sea, have provided further additions to the Indian marine fauna. In the manuscript, a new species, Periclimenella agattii sp. nov. is described and illustrated. The new species is morphologically most similar to P. spinifera among other congeners, but it strongly differs from that species by having upper the antennular flagellum with 14-16 segments, short free ramus with 12-13 segments, lower antennal flagellum thin and bearing 35-37 segments; 4 minute lateral spines on basal segment of 3rd maxilliped; male palm:carpus ratio of second pereopod higher than in female, propodus of 3rd pereopod with 7-8 ventral spines and hepatic spine with groove. Genetic analysis using the mitochondrial COI and 16S rRNA genes sequences proved that, the new species is significantly distinct from the closed related species.

In vitro antioxidant properties of fucoidan fractions from Sargassum tenerrimum.

The aim of the present study is conducted to evaluate the antioxidant potential and toxicity effect of polysaccharide-fucoidan from the brown seaweed Sargassum tenerrimum. Fucoidan-a sulphated polysaccharide contains fucose and sulphate as major compounds. Interestingly, various studies reported that the presence of sulphate content of the sample plays a significant role in pharmacological activities. In this study, fucoidan was fractionated by Ion exchange chromatography method and it major chemical constituent sulphate and fucose was determined by the biochemical methods. The toxicity effect of fucoidan was analyzed by the brine shrimp toxicity assay. Three fucoidan fractions (F1, F2 and F3) were obtained from Intact Fucoidan (IF) through anion-exchange column chromatography. In vitro antioxidant capability was analyzed by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), superoxide radical scavenging and total antioxidant assays and intact fucoidan showed the maximum activity 83.66 +/- 0.35, 81.73 +/- 0.35% and 41.6 +/- 0.43 mg g(-1), respectively. The finding of the present study was confirmed that the antioxidant property of fucoidan was depending upon the sulphate content of the fraction and these studies proved that fucoidan have non toxicity effect. Hence, fucoidan have the scope of being used as natural antioxidants in treating many human diseases.

Influence of host anemone (Stichodactyla haddoni, saville-kent, 1893) locomotion on its resident anemonefish reproduction.

Anemonefish are found commonly in reef habitats and they select only limited anemone species to exist their life. This study describes the movement of anemone, Stichodactyla haddoni and its impact on the reproduction of anemonefishes in captivity. The anemone movement was found to be creeping and in straight-line between successive positions (based on overlay mapping). The distance traveled by the host with (60%) and without substrate (20%) varied significantly (P<0.05) at a random direction. Spawning interval of the resident fish (3-4 days) increased significantly to 8-12 days (P<0.001) because of anemone mobility. Furthermore, host locomotion affected the embryonic development of harbored fish clutches. Percentage of egg maturity (3.5-35.3%) showed an exponential decrease with increase in the distance of substrate from the clutches, from 98 to 100% in the absence of host mobility to 3.5-35% with movement of >60cm. This study concludes that the sedentary habitat would enhance the reproduction value of the harbored fish. Further, in captivity providing with a substrate, supplying regular feed and good light intensity could prevent anemone migration and its implications on the reproductive success of the anemonefish.

Hatchery production of the clownfish Amphiprion nigripes at Agatti Island, Lakshadweep, India.

Healthy individuals of matured clownfish, Amphiprion nigripes and sea anemone, Heteractis magnifica were collected from the Agatti island lagoon by snorkeling. During 'conditioning' for 3 months, pair formation occurred and the same were transferred to rectangular fiber glass spawning tanks of 10001 capacity. Suitable water quality parameters were maintained. The fishes were fed with tuna eggs, boiled clam meat, squid, octopus and trash fish thrice in a day. Reproductive behaviour and embryonic development were documented. Spawning took place in between 0900 - 1100 hr and hatched-out occurs, after sunset following an incubation period of 8-9 days. Size of the newly laid egg was 2.0-2.2 mm in length and 1.0-1.2 mm in width. The larval rearing tanks were maintained with UV-treated water and followed the optimal physico-chemical parameters as in the parent tanks. The different light regimes and diets were used for the successful larval rearing. The maximum larval survival (61%) was achieved at the photoperiod of 24 L/0D. Within 15-17 days, the larvae metamorphosed and took up parent colouration and comparatively high growth rate was observed when fed on algae enriched rotifer than those with poly unsaturated fatty acid (PUFA).

Anti-dermatophytic activity of marine sponge, Sigmadocia carnosa (Dendy) on clinically isolated fungi.

OBJECTIVE: To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa (S. carnosa) against four dermatophytic fungi. METHODS: The methanol, ethyl acetate and acetone extract of marine sponge, S. carnosa was examined against Trichophyton mentagrophytes (T. mentagrophytes), Trichophyton rubrum (T. rubrum), Epidermophyton floccosum (E. floccosum) and Microsporum gypseum (M. gypseum) and qualitative analysed to find out the active molecules. RESULTS: The methanol extract of sponge was expressed significant activity than ethyl acetate and acetone. The minimum inhibitory concentration (MIC) of methanol extract of sponge that resulted in complete growth inhibition of T. mentagrophytes, T. rubrum, E. floccosum and M. gypseum were found to 125, 250, 250 and 250 µg/mL respectively. But, 100 % inhibition of fungal spore germination was observed in T. mentagrophytes at 500 µg/mL concentration followed by T. rubrum, E. floccosum and M. gypseum at 1 000 µg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophytic fungi. Methanol extracts showed presence of terpenoids, steroids, alkaloids, saponins and glycosides. CONCLUSION: Based on the literature, this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with S. carnosa. Further research also needs to purify and characterize the secondary metabolites from the sponge, S. carnosa for the valuable source of novel substances for future drug discovery.

Effect of neem extract against the bacteria isolated from marine fish.

Marine ornamental fishes are exceedingly valuable due to their high demand in domestic and international markets. There is a growing global interest to rear the fishes in captivity. But problem due to bacteria and fungi are the major hitch in captive condition. Since, the use of antibiotics is banned, an attempt was made to ascertain in vitro assay of the neem leaves extract against the bacterial pathogens isolated from infected fishes. Bacterial strains isolated from infected regions of the clown fishes Amphiprion sebae and A. ocellaris were identified as Aeromonas hydrophila, Enterobacter sp., E. coli, Pseudomonas aeruginosa, Proteus sp., Streptococcus sp., Vibrio cholerae, V. alginolyticus, V. parahaemolyticus and Yersinia enterocolitica. Ethanol and methanol extracts were highly inhibitory to the bacterial isolates when compared to other solvents. Ethanol extracts exhibited low minimum inhibitory concentration (75-250 microg ml(-1)) as compared to other extracts. The present finding revealed that the neem leaf extract significantly reduces the bacterial pathogens and their infection in marine ornamental fishes.