Fishery and Biological Aspects of Yellowfin Tuna Thunnus albacares along Andhra Coast, India

A potentially rich fishing ground for yellowfin tuna Thunnus albacares discovered off northern Andhra Pradesh along the east coast of India at depths of 200m and more is being gainfully exploited by the local fishers since 2002. Hooks and lines as well as trolls operated mostly from non-mechanized crafts (catamaran) are the major exploitation methods used. The mechanized sector ventured into oceanic tuna fishing during 2006 with the conversion of a few existing mechanized trawlers into long liners and for large scale commercial exploitation of yellowfin tuna in this region. The average annual (2004-2006) landing of tuna by the catamaran at Visakhapatnam was 1,515t. A wide size group represented the fishery with the fork length of T.albacares measuring from 25 cm to 190 cm with major modes at 90 and 130 cm. Fishes above 80 cm were found to be mature and the size at first maturity was estimated to be between 90-95 cm. Males were dominant with a male: female ratio of 1: 0.58. The length weight relationship is given by the formula W= 0.008634L 3.12. Food contents consisted of a variety of prey animals. Fishes (bony pelagic fishes), crustaceans (crabs and shrimps) and molluscs (squids) were the major prey groups. The fishery is still in its infancy and more research has to be carried out to understand its biology and formulate proper management measures to sustainably harvest this stock

Visual quality testing method used in the field for grading yellowfin tuna

The yellowfin tuna (Thunnus albacares) popularly known as the ‘chicken of the sea’ is harvested along the Indian coast mainly with an eye on the export market. Though the fish meat both in fresh and canned form has a demand in domestic markets in some states, the higher value it fetches in the export market prompts the fishermen to mainly aim at exports. However, certain minimal conditions of fish quality have to be ascertained and certified before it is accepted for export. The south-east Asian countries are the main market for tunas and tuna meat is consumed both in raw as well as processed forms (canned, fish fingers, fish powder, fish sauce etc.

Record size black marlin, Makaira indica (Cuvier, 1832) landed at Bhimilipatnam, Andhra Pradesh

A gigantic black marlin, Makaira indica measuring 4.3 m in length and weighing around 450 kg was landed at Bhimilipatnam beach landing centre and brought to Visakhapatnam Fishing Harbour

Contributions of Panchanan Maheshwari's school to angiosperm embryology through an integrative approach

P. Maheshwari who served as Professor and Head of the Department of Botany, University of Delhi from 1950 to 1966 built a flourishing school of embryology which became internationally recognized. His colleagues and students have contributed significantly to all areas of embryology through integrative approaches. In memory of his birth centenary year, we have prepared this article that summarizes the work done by his students and traces the phenomenal advances made in some areas in the post-Maheshwari era

Age, growth and population structure of the yellowfin tuna Thunnus albacares (Bonnaterre, 1788) exploited along the east coast of India

Lengths measurements of 6,758 yellowfin tuna (Thunnus albacares), landed by hook and line operators off eastern Indian coast were taken (20–185 cm FL) from 2003 to 2009. Age and growth were estimated using length based methods. The von Bertalanffy growth parameters estimated were L∝ = 197.42 cm, annual K= 0.30 and t0= -0.1157. Mortality estimates were M= 0.48 and Z= 0.71 and F= 0.23 with the exploitation ratio E= 0.32. Growth was rapid during the initial years when the annual growth increment was as high as 36.6 cm during the first year then which to as low as 3.3 cm in the tenth year. The fish attained a fork length of 56.2 cm at the end of one year. Size at maturity (87.5 cm) corresponded to an age of 1.7 years and the oldest individual in the sample was 9+ years (186 cm). The annual mean lengths varied from 80.6 cm to 115.3 cm with an average mean length of 101.9 cm. The fishery comprised of mostly adults with 64% comprising of fishes larger than size at first maturity

Feeding strategies and diet composition of yellowfin tuna Thunnus albacares (Bonnaterre, 1788) caught along Andhra Pradesh, east coast of India

The food of yellowfin tuna, Thunnus albacares caught by longlines off the east coast of India was studied in detail. Contents of 146 non-empty stomachs were analysed for the Index of relative importance (IRI) and prey specific abundance. T. albacares caught by the longline were found to be non-selective generalist feeders, foraging on micronektonic, pelagic or benthic organisms available in the epipelagic waters. Teleost fish, crabs, squids and shrimps were the major component of food items. Priacanthus hamrur was the most preyed upon fish with a high IRI (40.5%) followed by the swimming crab Charybdis smithii (23.9%), the squid Sthenoteuthis oualaniensis (15.5%) and prawn Solenocera hextii (10.3%). Being a large pelagic predator, it formed an important link in the food chain of the ocean system and also formed a good collector of the less exploited micronekton organisms of the deep scattering layer (DSL)

आँध्रप्रदेश की वेलापवर्ती मात्स्यिकी संपदाएं

आँध्रप्रदेश की वेलापवर्ती मात्स्यिकी संपदाए

Annual reproductive cycle of sea cucumber Holothuria (Halodeima) atra Jaeger (Holothuroidea : Aspidochirota) at Tuticorin, Southeast coast of India

Knowledge on population parameters is a pre-requisite for the rational management of holothurians. Infonnation on the various species is scarce despite their abundance and size, which qualify them as a significant component of the benthic macrofauna of lagoon and coral environments. The reproductive biology studies of sea cucumbers are of great importance in understanding the annual breeding season, recruitment panems and stock enhancement in the natural environment. Likewise, it also helps in establishing a hatchery system to produce seeds. Induced spawning could be achieved through thennal stimulation for seed production. This enhances importance of a species for mariculture activities, where adequate seed supply is an important criterion. Seasonal reproduction is a mode associated with the storage of gametes. followed by subsequent release in a mass spawn-Qut. It implies a non-random allocation of resources to reproductive activities in relation to environmental and biological inputs. Holorhuria arra is one of the commonest sea cucumbers in the tropical waters. It is well distributed in the Indo-West Pacific. Oriental and Australian regions. In India, it is reported from the Gulf of Kutchh, Bombay (Mumbai), Ramagiri , Goa. Karwar, Quilon, Vizhinjam , Kanyal.:urnari, Gulf of Mannar, Palk Bay, Madras (Chennai) , Visakhapamam, the Lakshadweep islands and the Andaman and Nicobar islands. This species occurs in shallow waters in good densities. In Tuticorin port region, about 5-8 specimens could be found in 10 sq. m. area. Many holothurians possess saponin-based toxin In their body. The degree of toxicity varies with each species. This toxin is found to inhibit bacterial and fungal action. When H. arra is handled in live condition. a red toxin known as holothurin, stains hand. Rao er at. (l985a and b;1991) states that the toxins of H. arra are of biomedical importance, since they exhibit anti-rumoural, anti-fertility and anti-cancerous properties. The toxins proved lethal for unwanted organisms in culture ponds during the experiments conducted by James (1986a). The significance of the toxins of H. arra in biomedical research enhances the potential commercial importance of the species. Many holothurian toxins are found to inhibit bacterial and fungal action

Apomixis and polyembryony in the guggul plant, Commiphora wightii

The present report is a part of our study on the reproductive biology of a traditional Indian medicinal plant,Commiphora wightii, a source of guggul steroids. Field examination showed a predominantly large number of isolated and groups of female individuals. Only one andromonoecious and two exclusively male plants were recorded. Female plants set seed irrespective of the presence or absence of pollen. Hand-pollination experiments and embryological studies have confirmed the occurrence of non-pseudogamous apomixis, nucellar polyembryony and autonomous endosperm formation for the first time in this plant, which is presently threatened by over-exploitation