The study emphasizes reproductive biomomics, population structure and length-weight relationship of spotted scat, Scatophagus argus , off Indian waters. Sampling from Ennore, Muttukadu, and Mandapam along the South-east coast of India registered their occurrence during the south-west monsoon (June to August) and north-east monsoon (October to December) with peaks during July and November. There exists a biased sex ratio towards females in the spotted scat population. Reproductivity performance was assessed based on the gonad-somatic index, which aptly correlated with peak spawning season. This led to a description of six stages of ovarian and testicular development. Histological studies further revealed five stages of oocyte and four stages of sperm maturation. Morphometric analysis indicated that the total length (TL) of the fish in the samples ranged from 9.2 cm to 18.3 cm in females and 12.0 cm to 17.6 cm in males. Length-weight equations of w = 0.0337 L 2.998 and w = 0.055 L 2.804 were derived for females and males, respectively. The relationship showed that the exponent “b” value was below 3, with a negative allometric equation documenting compressed body shape. This study provides baseline data on the population structure, length-weight relationship, sexual maturity, and spawning periodicity of Scatophagus argus in Indian waters.

This study emphasizes the need for sperm quality assessment and cryopreservation strategy in the spotted scat Scatophagus argus as the occurrence of male population of this species is limited. Analyses of sperm quality were made including ionic content and osmolality of seminal plasma and blood serum. Sodium chloride (0.9%) was optimized as the extender with a dilution ratio of 1:3 (milt:cryomedium) for all experiments. Cryoprotectants including dimethyl sulfoxide (DMSO), dimethyl acetamide (DMA), glycerol (GLY), propylene glycol (PG), ethylene glycol (EG) and methanol (MeOH) were screened at various concentrations and equilibration times. Cryopreservation was performed using the cryoprotectants DMSO, GLY, EG, and MeOH individually as well as in combinations. Experiment 1 was done with DMSO, GLY, EG and MeOH (5, 10 and 15%); experiment 2 was done with DMSO (5%) + GLY (5%), DMSO (5%) + EG (5%), DMSO (5%) + MeOH (5%). Simultaneously, experiment 3 was done with both cryoprotectants and co-cryoprotectants viz. DMSO (5%) + egg yolk (5%), DMSO (5%) + coconut water (5%), DMSO (5%) + tomato water (5%) and DMSO (5%) + honey (5%). The cooling sample was optimized and performed with a one-step freezing protocol of -5 degrees C/min from 25 degrees C to -150 degrees C. The results indicated that samples subjected to experiment 2 using DMSO (5%) + EG (5%) for 60 days of storage registered maximum motility (82.33 +/- 2.51%), duration time of sperm motility (10.45 +/- 1.01 min) and viability (84.14 +/- 5.29%) of post-thaw cryopreserved sperm. Morphology and ultrastructure of post-thaw sperm showed smooth surface topography and normal architecture of cellular organelles. Biochemical analysis indicated a reduction in the protein content of post-thaw cryopreserved sperm. DNA integrity (Comet assay) showed 6.30 +/- 1.00% of tail DNA in post-thaw sperm, whereas fresh sperm registered 2.41 +/- 1.85%. Functional integrity using the HOST of post-thaw sperm showed a maximum of 82.66 +/- 1.15% with DMSO (5%) + EG (5%). Finally, fertility of postthaw sperm using mature eggs of wild-caught females indicated the entry of sperm by breaking the vitelline membrane. Overall it was demonstrated that the DMSO (5%) + EG (5%) was amenable to the long-term preservation of sperm. Therefore, this protocol can be used as an alternative for male broodstock development under captive breeding program.

Microplastics (MPs) are ubiquitous in the marine environment, yet information regarding their occurrence in the food web is limited. We investigated the concentration and composition of MPs in water and diverse zooplankton groups from the Arabian Sea basin. Forty-one zooplankton tows were collected with a bongo net (330 μm mesh) from the Arabian Sea in January 2019. MPs in the surface water varied between 0 and 0.055 particles/m3, with a relatively higher concentration (0.013 ± 0.002 particles/m3) in the central Arabian Sea. Though fibrous MPs were most abundant in the seawater (77.14 %), zooplankton prefers small fragments (55.3 %). The size of MPs was distinctly smaller (277.1 ± 46.74 μm) in zooplankton than that in seawater (864.32 ± 73.72 μm), and MPs bioaccumulation was observed in almost all the zooplankton functional groups. Polymer composition revealed polyamide, polyethylene, polypropylene, and PVC were abundant in water and zooplankton, suggesting that the textile, fishing, shipping, and packaging industries are significant sources. The prevailing northeasterly winds, strong West India Coastal Current, and conducive westward radiated Rossby wave during January 2019 have carried the microplastic contaminated water mass away from the coast, posing a threat to the open ocean ecosystems. These results demand further attention to investigate the state of plastic pollution in the Arabian Sea basin.

This study evaluates the quality and optimization of cryopreservation protocol for sperm of Rachycentron canadum, (Cobia) by screening various cryoprotectants, extenders, freezing protocols and equilibration times. Earlier studies on toxicity assay confirmed the suitability of the extender marine fish ringer and cryoprotectants such as DMSO, EG and DMA for long-term storage. Experiments were performed with milt along with extender, cryoprotectants (DMSO, DMA and DMSO + EG) at dilution ratio of 1:40 and equilibration time of 15 s with single step freezing protocol (-6 degrees C/min from 4 C to -150 C and in LN2 at -196 C). The outcome of these experiments revealed that the sperm quality (motility, viability, functional integrity and DNA damage) was high with DMSO (5%) + EG (5%) compared to other individual and combination of cryoprotectants after 120 days storage. Maximum sperm motility of 62.8 +/- 2.7% and viability of 72.4 +/- 1.9% registered with DMSO (5%) + EG (5%). With reference to morphology, the post-thaw cryopreserved sperm of DMSO (5%) + EG (5%) showed intact sperm without any distortion. Under TEM also showed normal architecture of cellular organelles and plasma membrane. Metabolic enzymes activities (LDH, Asp and ALP), were high in post-thaw cryopreserved sperm with DMSO (5%) + EG (5%) compared to other cryoprotectants, but lesser than control. Similarly, antioxidant enzymes (SOD, GPx and LPO) registered high with DMSO (5%) + EG (5%), but low LPO compared to other cryoprotectants. Comet assay of post-thaw cryopreserved sperm of 120 days storage showed minimum DNA damage (5.84 & PLUSMN; 1.8%) with DMSO (5%) + EG (5%). Functional integrity of post-thaw cryopreserved sperm registered maximum of 68.7 +/- 3.6% with DMSO (5%) + EG (5%). This protocol thus established remarkable cryoresistance of cobia sperm; imply to be amenable for long-term storage.

Bone tissue regeneration is augmented by biocompatible nanofiber scaffolds, that supports reliable and enhanced bone formation. Zinc is an essential mineral that is vital for routine skeletal growth and it emerges to be able to improve bone regeneration. Phytochemicals, particularly flavonoids have achieved prominent interest for their therapeutic ability, they have demonstrated promising effects on bone by encouraging osteoblastogenesis, which finally leads to bone formation. In this study, we have synthesized bioactive zinc(II) quercetin complex material and used for nanofibers scaffold fabrication to enhance bone tissue regeneration property. Two derivatives of zinc(II) quercetin complexes [(Zn(quercetin) (H2O)(2)) (Zn+Q), and Zn(quercetin)(phenanthroline) (Zn+Q(PHt)) have been synthesized and characterized using UV-Visible spectrophotometer and Fourier Transform-IR spectroscopy. The UV-Visible absorption and IR spectra prove the B-ring chelation of the flavonoid quercetin to zinc (II) rather C-ring chelation. The potential ability of the above synthesized metal complexes on osteogenesis and angiogenesis have been studied. Besides the bioactivity of the metal complexes, the control quercetin has also been examined. The chick embryo chorioallantoic membrane (CAM) assay demonstrated that the angiogenic parameters were increased by the (Zn+Q(PHt)) complex. Amongst, (Zn+Q(PHt)) complex showed significant activity and thereby this complex has been further examined for the bone tissue activity by incorporating the complex into a nanofiber through electrospinning method. At the molecular level, Runx2, mRNA and protein, ALP and type 1 collagen mRNAs, and osteoblast-specific microRNA, pre-mir-15b were examined using real time RT-PCR and Western blot assay. Histology studies showed that the (PCL/gelatin/Zn+Q(PHt)) was biocompatibility in-ovo. Overall, the present study showed that quercetin-zinc complex (Zn+Q(PHt)) incorporated into PCL/gelatin nanofiber can act as a pharmacological agent for treating bone associated defects and promote bone regeneration.

Ultrastructure and development of spermatozoa in cobia, Rachycentron canadum are described. Sections through the testis show different developmental stages viz, Spermatocytes, spermatids and sperm. Spermatozoa of R. canadum exhibit the configuration of uniflagellated, anacrosomal Type I aquasperm, typical for externally fertilizing fish. Mature spermatozoon is seen with a prominent head and long cylindrical flagellum. Ultrastructure of sperm shows invaginated 'U' shaped nucleus and other organelles. The mitochondrial matrix is electron-dense with irregular arrangement of the cristae. The nucleus reveals a deep invagination (nuclear fossa) in which the centriolar complex is located. The centriolar complex lies inside the nuclear fossa and is composed of a proximal and a distal centriole. The two centrioles are placed perpendicular to each other. The flagellum has a typical eukaryotic organization (microtubule doublets 9 + 2 pattern) and measures around 36.21 +/- 0.42 mu m in length. This study for the first time provides a comprehensive detail on the ultrastructure and developmental process of sperm in cobia, R. canadum.

The present study documents the occurrence of an intersex condition in a natural population of mullet Mugil cephalus L. On closure examination of the dissected fish, 11 females and 7 males were recorded. Histological observations through the testes indicated that one of the male fish showed different developmental stages of oocytes in between the seminiferous tubules. Interestingly, the condition reported here did not show any internal bilateral division of the reproductive system into male and female components. But it had shown the occurrence of oocytes and spermatozoa throughout the entire region of the testis of a functional male. The observation of intersex testis or testicular oocytes (TO) is of first report from the east coast of India. The fish being catadromous, this condition may be related to possible accumulation of chemical contaminants in the habitat water.

This study documents the cascade of events that occurred in the coast and biota of the Chennai region exposed to an accidental oil spill near the Ennore port after the collision of two cargo ships. The impact of the collision was so severe that the oil compartment was damaged, spilling approximately 22 tonnes of oil at initial hours. Due to waves, tidal action and southern current, the spillage travelled a long distance up to a stretch of around 52 km along the coastline in Bay of Bengal. Damage to the biota was monitored at different zones based on the intensity of the oil spill to evaluate the environmental impact caused by it. The shorelines of most of these areas had shown signs of oil sludge deposited in the sediments and boulders from the very next day of the collision. An intensive survey indicated that the sea turtles, crabs, fishes and seaweeds were washed ashore that posed a threat to the coastal habitat. Further, in-depth, histological studies on gills, hepatopancreas and eggs of the crab Grapsus albolineatus, showed structural deformities with irregular gill tips and lower haemocytes counts in the gill samples. Whereas hepatopancreas and eggs did not show any structural deformities, although they appeared black due to adhesion of oil, but no sign of oil in the internal region. This pilot study provides baseline information about the post oil spill scenario of the coastal region as alarming and a threat to ecologically sensitive marine organisms. Available online at: www.mbai.org.in doi: 10.6024/jmbai.2017.59.2.1989-08

This study focused on the quality of sperm obtained from spermatophores of cadaveric shrimp after long-term storage. Spermatophores were collected using the stripping method, which has resulted in maximum sperm viability when this approach was previously used. Cryoprotectants toxicity assessment of samples was conducted using dimethyl sulfoxide (DMSO), methanol (MeOH), ethylene glycol (EG), glycerol (Gly), dimethyl acetamide (DMA) and propylene glycol (PG) at different concentrations (5%, 10% and 30% v/v), prepared in Ca-F saline. Based on the results from the cryoprotectant toxicity assay, DMSO and MeOH were used individually as well as in combination for the subsequent study. Samples along with cryoprotectants were subjected to slow and fast freezing protocols (i.e. -0.5, and -10 degrees C/min to a final temperature of -80 degrees C) and were subsequently stored in LN2 (196 degrees C). Similarly, vitrification was performed by plunging the samples directly in to LN2. Samples of control and cryopreserved spermatophores that were stored for 45 days had sperm viabilities of 91.4 +/- 3.6% and 53.9 +/- 4.7%, respectively. Further observations with HOST and DNA integrity analyses of the cryopreserved sperm, resulted in percentages of 45.6 +/- 4.2%; 58.1 +/- 1.7% compared to control values of 82.3 +/- 4.8%; 94.3 +/- 1.9%, respectively. Use of the one-step slow freezing protocol at the rate of -0.5 degrees C/min between 4 degrees C and -80 degrees C in LN2 with DMSO (5%) + MeOH (5%) was a desirable preservation strategy of spermatophores, compared to other freezing protocols. Unlike sperm viability, the HOST results affirm the fertility potential of the sperm that have the capacity to participate in the fertilization process. Thus, the results of this study demonstrate that long term storage of sperm in spermatophores of Fenneropenaeus indicus collected from cadaveric specimens can result in viable sperm after cryopreservation if extender (Ca-F saline) containing DMSO and MeOH are used.

Ultrastructure of spermatozoa in fairy shrimp Streptocephalus dichotomus revealed that they are amoeboid type with no acrosome and flagella. Surface topography of the spermatozoon is smooth with occasional pseudopodial projections. Transmission electron micrographs of spermatozoa show organelle and the mitochondria which is not fused to form the so called ‘Nebenkern’. The testicular lumen reveals spermatozoa in varying sizes and shapes.

This study evaluates freezing protocol with suitable cryoprotectants and their effects on the fertility potential of sperm in the cryopreserved spermatophores of Macrobrachium rosenbergii. Spermatophores, collected using electroejaculation, were suspended in dimethyl sulfoxide (DMSO), propylene glycol (PG), methanol, glycerol and ethylene glycol (EG) at different concentrations (10, 15 & 20% v/v), prepared in sterile-filtered pond water. Based on the cryoprotectant toxicity assay, DMSO and PG were used individually as well as in combination with three freezing protocols (i.e. -1.5, -3 and -5°C/min and to final temperature of -39°C) and plunged into liquid nitrogen at -196°C. After 90 days of storage (-196°C) thawing was done at 35°C in a water bath for 1min. Results showed that fresh and cryopreserved spermatophores held for 90 days registered sperm viability of 91.4±2.9% and 50.4±1.9% respectively. Further, fertility potential of sperm was assessed based on acrosome reactivity using calcium ionophore (A23187). Observations indicated that cryopreserved sperm registered 28.3±2.2% of acrosome reactivity compared to freshly collected spermatophores (85.3±2.5%). Thus, one-step slow cooling rate of -1.5°C/min between 27°C and -39°C stored in liquid nitrogen at -196°C with DMSO (10%)+PG (10%) seems to be amenable for cryopreservation of spermatophores, compared to other cooling rates.