Strong seasonal upwelling, downwelling, changes in current patterns and the volume of freshwater discharge from Cochin Estuary defines the coastal waters off Cochin. These coastal waters were investigated through monthly sampling efforts during March 2015 to February 2016 to study the seasonal and spatial variability in bio-optical properties for the four different seasons mainly Spring Inter Monsoon (SIM), South West Monsoon (SWM), Fall Inter Monsoon (FIM) and Winter Monsoon (WM). The Barmouth region is the meeting place where freshwater from Cochin Estuary directly enters to the sea through a single narrow outlet, was dominated by highly turbid waters during the entire period of study. Among the four seasons, chlorophyll a (Chl_a) concentration showed a high value during SWM, ranged from 2.90 to 11.66 mg m −3 with an average value of 6.56 ± 3.51 mg m −3. During SIM the distribution of coloured dissolved organic matter (CDOM) is controlled by decomposition of phytoplankton biomass and the river discharge, whereas during SWM the temporal distribution of CDOM is controlled only by river discharge. The highest value for CDOM spectral slope (S CDOM) was observed during SWM, ranged from 0.013 to 0.020 nm −1 with an average value of 0.015 ± 0.002 nm −1. During WM, the high S CDOM with lower a CDOM (443) indicates the photo-degradation affects the absorption characteristics of CDOM. The observed nonlinearity between Chl_a and the ratio of phytoplankton absorption a ph (443)/a ph (670) indicating the packaging effect and changes in the intercellular composition of pigments. During the study period, a ph (670) was strongly correlated with Chl_a than a ph (443), which explains the accessory pigment absorption dominating more than Chl_a in the blue part of the spectrum. Similarly, the results obtained from seasonal bio-optical data indicating that Chl_a significantly contributes light attenuation of the water column during SIM, whereas detritus (a d) significantly contributes light attenuation during SIM and WM. During the study period, the relative absorption of detritus materials dominates the relative absorption of phytoplankton and CDOM at 443, 555 and 670 nm wavelengths.

In tropical shrimp farms, especially in traditional pokkali shrimp ponds, poor water quality management can lead to serious threats like heavy algal blooms and frequent disease outbreaks. An investigation regarding the frequent disease outbreaks in selected pokkali shrimp pond adjoining the Cochin backwaters has been conducted. Water quality parameters were analyzed during the study period. Results indicate a considerable fluctuation in the concentration of dissolved oxygen (DO) in the study in the shrimp farm where the algal bloom was observed. Poor water exchange along with nutrient loading from adjacent housing areas resulted in heavy algal bloom in the pond which led to hypoxic conditions in early morning and supersaturation of DO in the afternoon. It also led to considerably high alkaline pH. High levels of total ammonia nitrogen (TAN) were recorded in the sampling sites. Heavy algal bloom was observed throughout the study period in the selected pond especially in the summer. Anabaenopsis elenkinii and Merismopedia elagans which were the dominant species from the culture pond caused the bloom. Characterization and percentage distribution of bacteria present in the water and those associated with the algal blooms were carried out. The algae were found to support greater diversity of bacteria when compared to water. Pathogenic species like Aeromonas hydrophila and Vibrio parahaemolyticus were encountered in the study. Experimental challenge studies using Artemia as a model showed that the V. parahaemolyticus isolates were highly pathogenic. Hence, this study reveals how algal growth supports opportunistic pathogens in great diverse in a shrimp pond and causes frequent disease outbreaks under favourable conditions.

Zoosystema est distribué en version électronique par / Zoosystema is distributed electronically by: -BioOne ® (http://www.bioone.org) Les articles ainsi que les nouveautés nomenclaturales publiés dans Zoosystema sont référencés par / Articles and nomenclatural novelties published in Zoosystema are referenced by: -ZooBank ® (http://zoobank.org) PHOTOCOPIES : Les Publications scientifiques du Muséum adhèrent au Centre Français d'Exploitation du Droit de Copie (CFC), 20 rue des Grands Augustins, 75006

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The Smallfin Gulper Shark Centrophorus moluccensis is reported for the first time from the Andaman & Nicobar waters of the Indian EEZ.  A male specimen of 785mm total length and weighing 2.34kg was landed by a motorized longliner at Burmanallah, South Andaman District.  The specimen was caught off Chidiyatapu, South Andaman at a depth of 250m.  A detailed morphological description of the specimen and comparison with previous literature is provided.

This manuscript deals with the Bent-fin Devil Ray Mobula thurstoni for its first time occurrence in the Andaman & Nicobar waters around the Indian EEZ which is a new locality record confirming the range extension of the species to the southeast of Bay of Bengal (the Andaman Sea).  A female specimen of 318mm disc length and weighing 2.47Kg was caught by a multiday bottom trawler operated off North Bay and was landed at Junglighat fishing harbour, South Andaman.  A detailed diagnostic description and morphometric measurements of M. thurstoni is provided.  For the first time this species has been described from Indian waters and compared with the other related species, and so documenting its first occurrence in the Andaman & Nicobar waters.

Length-weight relationships (LWR) for eight deep-sea fishes belonging to six families collected from the south west coast of India are presented. Specimens were caught by deep-sea shrimp trawls with mesh size 24 mm during 2011 and 2013. The b values ranged from 2.13 to 3.71 and the coefficient of determination (r 2 ) ranged from 0.84 to 0.98. A new standard length maximum was recorded for Neoscopelus microchir. The b values estimated during the present study were compared with the values estimated using models based on Bayesian approach deposited in Fish Base. How to cite this article: Bineesh KK, Nashad M, Aneesh Kumar KV, Akhilesh KV, Hashim M. Length-weight relationships of eight deep-sea fish species collected from the southwest coast of India.

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