Absorption of food in the black-jaw tilapia, Sarotherodon melanotheron (Ruppell) from a small tropical man-made lake in Ibadan, Nigeria

The carbohydrate, protein and lipid contents of the food ingested and their absorption in the intestine of Sarotherodon melanotheron inhabiting Awba lake in Ibadan, Nigeria, were investigated. Total carbohydrates of the ingested food ranged from 39.33 to 55.38% (mean = 48.70% while total protein and total lipid ranged from 10.10 to 17.13% (mean = 12.91%) and 7.79 to 8.96% (mean = 8.28%) dry weight, respectively. Calculated total percentages absorbed were 54.86-62.01 (mean 58.07) carbohydrates 47.33-54.06 (mean = 50.43) protein and 43.27-52.23% (mean 46.56) lipid. Absorption of protein and carbohydrate occurred mostly in the fore-gut (the first one-third of the intestine), while lipid was mostly absorbed in the mid-gut (the second one-third of the intestine). Dietary carbohydrate, protein and lipid contents of the food as well as the absorptive capacity of the intestine for these components of the food varied with size of fish

The Black Clam, Villorita cyprinoides, Fishery in the State of Kerala, India

The black clam, Villorita cyprinoides, is the most important clam species landed in India. The State of Kerala has been, by far, the leading producer of the species. Nearly all the landings, about 25,000 tons (t)/year are harvested in Vembanad Lake, the largest estuary, 96 km (54 mi) long, on the west coast of India. Nearly 4,000 fishermen harvest the black clams year-round. They harvest most by hand while diving in waters from 2.1–2.7 m (7–9 ft) deep. Each collects 150–200 kg (3–5 bushels)/day. Upon returning from the harvesting beds, the fishermen and their families cook the clams and separate their meats from their shells using simple sieves. Fishermen’s wives sell the meats within their local villages and save some for their families to eat. The shells are sold through organized fishermen societies to various industries. A substantial quantity of sub-fossil black clam shells lies buried from 22–50 cm (9–20 in) beneath the lake sediments. They are dredged in a controlled manner and sold to the same industries. The stocks of black clams seem to be declining slowly in the southern part of the lake because the water has been getting fresher, but they are not declining in the northern half. A likely threat to the landings may be a lack of fishermen in the future.

Trade of live brooders of the black tiger shrimp, Penaeus Monodon Fabricius 1978, at Visakhapatnam, Andhra Pradesh

The demand for brooders of Penaeus monodon by the hatcheries, which are solely dependant on wild brooders for their seed production, has resulted in a vigorous fishery and trade for this species, especially along the Visakhapatnam coast. More than three hundred brooders are brought in per day for trading during the peak landing season from December to March every year. The price of gravid brooders has been declining over the years but on an average is about Rs. 30,000 per brooder. The total length of male brooders ranged from 190 to 246 mm during the three years under study and for females it varied between 210 and 330 mm. A specialized methodology for transportation, storage and trade of P. monodon brooders has been evolved over the years at Visakhapatnam Fishing Harbour. Concentrated exploitation of brooders from the wild and presence of pathogens in them makes a strong case for development of specific pathogen free brooders and conservation of wild stock.

A program for the identification of the pelagic eggs of Black Sea fishes

A computer program was developed for the identification of the teleost fish eggs that may be found in the pelagic zone of the Black Sea. The program identifies eggs of 70 species, using up to 28 descriptive characters, and may be adapted for use outside of the Black Sea.

An assessment of scup (Stenotomus chrysops) and black sea bass (Centropristas striata) discards in the directed otter trawl fisheries in the Mid-Atlantic Bight

This study was undertaken to re-assess the level of scup (Stenotomus chrysops) discards by weight and to evaluate the effect of various codend mesh sizes on the level of scup discards in the winter-trawl scup fishery. Scup discards were high in directed scup tows regardless of codend mesh — typically one to five times the weight of landings. The weight of scup discards in the present study did not differ significantly from that recorded in scup-targeted tows in the NMFS observer database. Most discards were required as such by the 22.86 cm TL (total length) fish-size limit for catches. Mesh sizes ≤12.7 cm, including the current legal mesh size (11.43 cm) did not adequately filter out scup smaller than 22.86 cm. The median length of scup discards was about 19.83 cm TL. Lowering the legal size for scup from 22.86 to 19.83 cm TL would greatly reduce discard mortality. Scup discards were a small fraction (0.4%) of black sea bass (Centropristis striata) landings in blacksea-bass−targeted tows. The black sea bass fishery is currently regulated under the small-mesh fishery gearrestricted area plan in which fishing is prohibited in some areas to reduce scup mortality. Our study found no evidence to support the efficacy of this management approach. The expectations that discarding would increase disproportionately as the trip limit (limit [in kilograms] on catch for a species) was reached towards the end of the trip and that discards would increase when the trip limit was reduced from 4536 kg to 454 kg at the end of the directed fishing season were not supported. Trip limits did not significantly affect discard mortality.

Reproductive biology of Black Anglerfish (Lophius budegassa) in the northwestern Mediterranean Sea

Gonadal morphology and reproductive biology of the Black Anglerfish (Lophius budegassa) were studied by examining 4410 specimens collected between June 2007 and December 2010 in the northwestern Mediterranean Sea. Ovaries and testes presented traits common among fishes of the order Lophiiformes. Spawning occurred between November and March. Size at first maturity (L50) was 33.4 cm in total length (TL) for males and 48.2 cm TL for females. Black Anglerfish is a total spawner with group-synchronous oocyte development and determinate fecundity. Fecundity values ranged from 87,569 to 398,986 oocytes, and mean potential fecundity was estimated at 78,929 (standard error of the mean [SE] 13,648) oocytes per kilogram of mature female. This study provides the first description of the presence of 2–3 eggs sharing the same chamber and a semicystic type of spermatogenesis for Black Anglerfish. This new information allows for a better understanding of Black Anglerfish reproduction—knowledge that will be useful for the assessment and management of this species.