Field Identification of Major Elasmobranchs along the Indian Coast

Elasmobranchs are an important group of demersal fishes which are represented by sharks, skates and rays. India is the world’s second biggest shark fishing nation next to Indonesia. They belong to the Class Elasmobranchii under the Phylum Chordata. Sharks are caught with various gears like drift gillnets, longlines, hooks and line units and are landed throughout the year. They feed on bony fishes, other sharks, rays, crustaceans and squids

Decadal Trends of Indian Demersal Fisheries

Fisheries sector plays an important role in the overall socio-economic development of India. India is one of the major fish producing countries in the world contributing over 3% of both marine and freshwater fishes of the world production. Marine fishes, based on their depth-wise distribution are grouped mainly as pelagic and demersal, the former occupying surface and subsurface waters and the latter the neritic areas in the continental shelf. Demersal fishes are those fishes which can either rest on the sea floor or which can float in the water column just above the sea floor. The demersal fish resources of India include the elasmobranchs, eels, major perches, threadfin breams, silverbellies, sciaenids, lizardfishes, pomfrets, bulls eye, catfishes, flatfishes, goatfish and white fish. There is a significant contribution by the demersal fishes to the total Indian marine fish landings. When compared to the pelagic resources, proper exploitation of the demersal finfishes in India has been initiated since 1960-62 period. With the introduction of mechanized bottom trawling the exploitation of demersal finfishes attained a 2.7 fold increase reaching 0.52 million tonnes in the late eighties from 0.08million tonnes during the late fifties. In 2017, the demersal fish production of India reached new heights with a peak annual average landing of 1 million tonne which is almost an increase of 12.5 fold from the late fifties. The annual average landings of demersal finfishes along the Indian coast during 2010-2015 was accounted to 0.95 million tonnes contributing 26.32% to the total landings. However, the catch share of demersal finfishes during the last 35 years indicates that the contribution of demersal finfishes to the total Indian marine landings is decreasing over the years. The maximum share was reported in 1983 with 33% contribution and the lowest share was in 1989

\u3ci\u3eSelachohemecus benzi\u3c/i\u3e n. sp. (Digenea: Sanguinicolidae) from the Blacktip Shark \u3ci\u3eCarcharhinus limbatus\u3c/i\u3e (Carcharhinidae) in the Northern Gulf of Mexico

Selachohemecus benzi Bullard & Overstreet n. sp. infects the heart and kidney of the blacktip shark Carcharhinus limbatus in the northern Gulf of Mexico off Florida and Mississippi, USA. Specimens of S. olsoni Short, 1954, the only congener and only other named blood fluke reported from a chondrichthyan in the Gulf of Mexico, were collected from the heart of the Atlantic sharpnose shark Rhizoprionodon terraenovae from two new localities, Apalachicola Bay, Florida, and Mississippi Sound, Mississippi, USA. The new species differs from S. olsoni by having a larger body (1.4–3.8 mm long), robust tegumental body spines numbering 51–63 along each lateral body margin, a testis extending from the posterior caeca to the ovary, and a medial ovary with lobes. We amend the diagnosis of Selachohemecus Short, 1954 to accommodate it and provide a diagnostic key for all named chondrichthyan blood flukes

Check list of fishes of the Gulf of Mannar ecosystem, Tamil Nadu, India

Gulf of Mannar Ecosystem (GOME) covers an area spread over Rameswaram and Kanyakumari for about 19000 km2 and lies between 78°11’E and 79°15’ E longitude and 8°49’N and 9°15’N latitude. The 21 coral islands form a network of habitats for different kinds of fishes and marine organisms. Fish samples were collected during April 2005 to March 2010 from different centers viz., Vembar, Tharuvaikulam, Vellapatti, Therespuram, Tuticorin, Alangarathattu, Pazhaykayal, Punnakayal, Kayalpattinam, Veerapandiapattinam, Thiruchendur and Manappad of Gulf of Mannar ecosystem. The present check list was the first attempt to produce a systematic list of fishes found in the Gulf of Mannar ecosystem. It includes 476 genera and 1182 species in 144 families and 39 orders, of which 628 species have been recorded in the present study

Morfometría corporal, diversidad natatoria y nicho de los tiburones demersales: estudio comparativo en el mar Mediterráneo

Seven demersal shark species belonging to six families, obtained from the southern Mediterranean Sea, were selected as representative of different putative swimming modes, inhabited depths and trophic levels. Caudal fin morphometrics (caudal fin span, area and aspect ratio), hepatosomatic index and muscular-skeletal amount per unit length were estimated and compared within and among species by means of both parametric and non-parametric multivariate and univariate statistical procedures. Intra-specific variation was related to size and, for one species only, also to sex. Two inter-specific patterns of variation were observed: the first pattern was interpreted as a swimming ability gradient between slow benthic and more pelagic species, as a function of caudal morphometry and body characteristics; the second pattern is related to the depth the species inhabit and/or their trophic level. These two hypotheses were tested with the current data and literature information, and discussed in the context of shark swimming modes, habit and environment. Based on observed differences in caudal fin morphometrics, liver and muscular masses, this paper is the first to provide a quantitative and comparative dataset for demersal sharks as a group, and attempts to describe sample variability as a function of expected swimming ability and occupied niche (depth inhabited and/or trophic level).Siete especies de tiburones demersales, pertenecientes a 6 familias, capturadas en el sur del mar Mediterráneo, fueron seleccionadas como representantes de diferentes modos de natación, profundidad que suelen habitar y niveles tróficos. La morfometría de la aleta caudal (longitud, área y relación de aspecto), el índice hepato¬somático y la relación entre músculo y esqueleto por unidad de longitud fueron determinados y comparados entre los indivi¬duos y entre especies a través de procedimientos estadísticos paramétricos y no paramétricos, multivariados y univariados. La variación intra-específica se relacionó con el tamaño y, para una única especie, también con el sexo. Se observaron dos patrones interespecíficos de variación: el primero fue interpretado como un gradiente de la capacidad de natación entre es-pecies bentónicas y las más pelágicas, en función de la morfometría caudal y de las características corporales. El segundo se debió principalmente a la profundidad habitada y / o el nivel trófico. Asociando los datos actuales a la información existente en la literatura, estas dos hipótesis se comprobaron y se examinaron en el contexto del tipo de natación del tiburón y el am¬biente marino. Apartir de las diferencias observadas en la morfometría de la aleta caudal, el hígado y las masas musculares, este documento ofrece por primera vez una base de datos cuantitativos y comparativos sobre los tiburones demersales, como grupo, intentando describir la variabilidad muestral como una función de la capacidad de natación esperada y de los nichos ocupados (profundidad habitada y/ o nivel trófico)

Overview of the Fish Diversity of Indian Waters

Fishing is one of the oldest human activities and it developed gradually, when our ancestors moved from the collection of plants and animals to hunting by using tools and weapons. The oldest fishing implements so far identified are harpoons, found in the territory of Congo, and dating about 90,000 years. Interestingly, these harpoons were found associated with the bones of a species of now extinct giant catfish. In India too, it is believed that the development of fishing must have been parallel. There are reports that fishes were grown in reservoirs as early as 320 BC. There are several evidences of fish capture and culture since then. There were evidences to indicate over-fishing in the River Ganges as early as 1785. Russell made the first systematic study of the Indian fish fauna from 1785 to 1789 AD. Sir Francis Day studied the systematics of Indian fishes for over 20 years and listed 351 genera and 1418 species of marine, brackish water and freshwater fishes in 1868. Later, Alcock added 86 new genera and 200 species to the list. Jones and Kumaran (1980) recorded 603 species of fish from the Laccadive archipelago. Of the 603 species of marine fishes belonging to 126 families that are reported from the islands, at least 300 species belong to the ornamental fish category. At present, of the recorded 24,000 species of finfishes in the world, about 2364 species are known to occur in India (www. fishbase. org). Rao (2009) recorded 1371 species in 77 families from the Andaman and Nicobar islands

Kennisvraag haaien: wat is er bekend over haaien voor de voor Nederland relevante gebieden?

Op basis van expert-judgement van IMARES medewerkers en buitenlandse collega’s, wetenschappelijke artikelen, rapporten en het internet, is een grove verkenning uitgevoerd naar (i) wat er bekend is over haaienbestanden, vangsten, monitoring en visserij voor de gebieden die relevant zijn voor Nederland (ii) welke afspraken gemaakt zijn over de vangst van haaien door de verschillende RFMOs (Regional Fisheries Management Organisations) waar Nederland lid van is

Monitoring the recovery of exploited deep-water species

Commercial fisheries for deep-water species off the Irish coast developed in the late 1990s and declined in the early 2000s. Many of the exploited stocks were depleted a result of commercial exploitation and ICES has advised a zero catch for Orange Roughy since 2004, and for Portuguese Dogfish and Leafscale Gulper shark since 2005. Since 2016, the deep water access regulation has effectively banned trawling in waters deeper than 800 m (EC, 2016) and fishing for deep-water sharks with static netting >600 m is also banned by the technical measures regulation (EC, 2019). However, some of these species continue to be caught, either by gears not covered by this regulation or in water <800 m deep. The Marine Institute carried out a survey programme to assess the distribution and abundance of these species between 1992 and 1999 and again between 2006 and 2009. Since 2019, 3 days of the Irish Anglerfish and Megrim Survey have been allocated to monitoring the recovery of commercial deep-water species. This work was funded under the European Maritime and Fisheries Fund (EMFF) from 2019 to 2021 and European Maritime, Fisheries and Aquaculture Fund (EMFAF) since 2022. The main objective of the current project is to assess the recovery of exploited deep-water species in Irish waters by comparing the results from 2019 to 2022 surveys with those from the previous period in 2006 to 2009 (methods used in the earlier period 1992 to 1999 were different, therefore a direct comparison with that period is not possible).EMFF, EMFAF, the project is co-funded by the Government of Ireland and the European Unio