Background: The epidermal mucus of fish contains various bioactive compounds, which play a crucial role in the animal defense mechanisms. However, the mucus from giant mudskipper is not well characterized for its biochemical and pharmacological effects. This study for the first time analyzed the mucus extracts of this species for antimicrobial (against human pathogen) and hemolytic activities. Fourier-transform infrared spectrum analysis (FT-IR) and SDS-PAGE of mucus extracts were also carried out. Results: The protein content in Periophthalmodon schlosseri (Gobiidae: Oxudercine) mucus extracts was 0.66 ± 0.04 mg/ml. The mucus extracts of P. schlosseri showed antibacterial activity against all eight human pathogenic bacteria and four fungal strains tested in this study. The hemolytic activities against chicken and human blood cells were observed with maximum activity for dichloromethane extracts. The FT-IR spectrum of mucus extract of P. schlosseri showed the presence of functional groups, evident protein bands of various molecular weights ranging from 14 kDa to 97 kDa. Conclusion: The obtained results suggested that the mucus of this species has proteinaceous compounds responsible for antimicrobial and hemolytic activities.

This research article reports an exhaustive account on the mangrove-associated polychaetes. Polychaetes are an important component in marine benthic communities and they play a major ecological role in mangrove ecosystem. This article gives an overview of polychaete diversity associated to five major mangrove forests of east coast of India (Muthupettai, Pichavaram, Coringa, Bhitarkanika and Sundarban). The results of this survey indicated that the physicochemical parameters did not vary much except a few parameters that showed only marginal variations. With regard to the macrobenthic organisms, the polychaetes topped the list. Crustaceans were found to be the next dominant group in the order of abundance and followed by gastropods and bivalves of the total benthic organisms collected. The results of the statistical analysis revealed that the parameters such as salinity, pH, silt, clay, total organic carbon (TOC), total nitrogen (TN) and total phosphate (TP) were manifested as best match in determining benthic fauna distributions followed by TOC, slit, clay and TP. The maximum number of polychaete species was recorded from Sundarban mangroves (68 species) and minimum in Muthupettai mangroves (39 species).

The mudskipper Pseudapocryptes elongatus (Cuvier, 1816), (Gobiidae) are caught throughout the year and they are considered as most edible mudskipper species in Sundarbans. They are targeted by special gears and sold live in large quantities in the local markets of Diamond Harbor, Namkhana and Kakdweep. The adult P. elongatus (14-18 cm total length) specimens were purchased from the Diamond Harbor landing center for evaluation of its biochemical components such as Protein, carbohydrate, lipid, amino acid, fatty acid, vitamin, and minerals. The percentage composition of protein was high (27.34%) followed by the carbohydrate (4.57%) and lipid (2.72%). The amino acids both essential (47.72%) and non-essential (42.91%) was found adequate. Among fatty acids, polyunsaturated fatty acid (PUFA) was found the maximum (31.55%) followed by saturated fatty acid (SFA; 27.66%) and monounsaturated fatty acid (MUFA; 19.55%). Vitamin A (112.5 IU/100 g) and Ca + (62.2 mg/100 g) were found maximum levels. The present finding supports that P. elongatus is valuable for human consumption due to its high-quality protein with well-balanced amino acids.

Bharadhirajan P, Mahadevan G, Murugesan P, Murugan S, Pouladi M, Abbaspour Naderi R. 2019. Relative condition factor, length-weight relationship, and growth of three-spotted flounder, Pseudorhombus triocellatus (Bloch & Schneider, 1801) from Parangipettai Coast, India. Biodiversitas 20: 373-379. The three-spotted flounder, Pseudorhombus triocellatus is usually caught as trawl by-catch from Parangipettai coastal waters but regrettably, limited information on its age structure and growth is available. Hence, the present study aims to understand some basic parameters of its biology and growth. A total of 759 specimens (360 males and 399 females) ranging from 4 cm to 13 cm in total length (TL) and 5.26-35.41 g in weight were collected from the trawl catches of Parangipettai and Mudasalodai landing center during January–December 2015. The estimated growth coefficient (b) value for males (2.797) was greater than 3 and for females (3.023) was less than 3. The relative condition factor (Kn) values of females were higher than males except during February, June, and September. The values of asymptotic length (L∞) obtained in this study using various methods didn’t vary significantly (P>0.05). The most appropriate values of asymptotic length (Lα) for males were 137.11 mm and for females were 141.75 mm. The most appropriate values of growth rate (K) for males were 0.397 yr-1 and for females were 0.410 yr-1. The estimated length at age 0 (t0) for males and females were 0.197 mm and 0.292 mm, respectively. The longevity (tmax) of males and females P. triocellatus were 2.04 years and 2.24 years, respectively. The result of this study provides basic information for future studies.

The length-weight relationships (LWR) of males and females of Periophthalmus novemradiatus and Boleophthalmus boddarti were estimated in the present study.Specimens were collected during March-2014 and February-2015 using scoop net, cast net and hand picking from Vellar estuary, Southeast coast of India. The results of this study will contribute to the knowledge of mudskippers biology and will serve as valuable baseline information. | 1359MAHADEVAN AND RAVI the month of July to September. The growth coefficient "b" values of the fishes were found between 2.74 and 2.89 and the r 2 values ranged from 0.964 to 0.986, with high degree of positive correlation between total body length and weight (Table 2). Froese (2006) proposed that the "b" value for an ideal fish may range between 2.5 to 4.0. This range pattern has been considered for several authors around the World (Andrade, Jesus, & Giarrizzo, 2015;Azevedo-Santos et al., 2018;Lima et al. , 2017). In the present study the "b" values of all five fishes (both males and females) ranged between 2.5 and 4.0. Khaironizam and Rashid (2002) estimated the LWR of eleven species of mudskippers from Selangor, Malaysia and he also reported the b values range between 2.56 and 3.50. The calculated b values for males and females varied comparatively which might be due to gonad maturity, habitat, metabolic rates, growth pattern, sex and stomach fullness (Wootton, 1990). | D ISCUSS I ON