Field Identification of Tunas from Indian Waters

The Family Scombridae is one of the largest and most economically important fish family which comprises of most advanced scombroid fishes such as mackerels, tunas and bonitos with 54 valid species in 15 genera (Collette et al., 2001). Among them, tunas are one of the important food fishes exploited all over the world. Altogether 9 species in 6 genera are contributing to the Indian tuna fisheries. Indian tunas are classified into two categories such as (i) Coastal tuna and (ii) Oceanic tuna. Euthynnus affinis, Auxis thazard, A. rochei, and Sarda orientalis are considered as coastal tuna where as Thunnus albacares, T. obesus, T. tonggol, Katsuwonus pelamis, and Gymnosarda unicolor are mostly oceanic in nature

Broodstock development, breeding, embryonic development and larviculture of spine-cheek anemonefish, Premnas biaculeatus (Bloch, 1790)

The broodstock development, breeding, embryonic development and larviculture of Premnas biaculeatus and different feeding and envrionmental conditioins are reported for the first tiem. The influence of enriched rotifer (Brachionus rotundiformis, Brachionus plicatilis) and non-enriched newly hatched Artemia nauplii along with microalgae (Chlorella marina, Nannochloropsis oculata and Isochrysis galbana) on larval rearing and survival was elucidated. Fishes in the length range of of 55 to 70 mm (presumptive male) and 120 to 150 mm (presumptive female) were selected for pair formation experiments along with single host sea anemone Heteractis magnifica. All the 10 pairs started spawning within four months after they were shifted to the breeding tanks. Eggs were laid in round patches or clutches at intervals of 15 to 20 days with an average of 2.09 ± 0.3 spawnings per month per pair giving an annual number of 1752 -11832 eggs per pair. Upon incubation for six days in complete darkness, 95-98% of the eggs hatched with the peak hatching between 1830 and 1930 hrs. On 20th day post-hatch (d.p.h.), most of the larvae metamorphosed to juveniles and began to shift from partially pelagic to epibenthic and the juveniles reached marketable size from 60th d.p.h. onwards

Life history pathways in false clown Amphiprion ocellaris Cuvier, 1830: A journey from egg to adult under captive condition

There is a vast literature on distribution, rearing conditions and behavioural studies of clownfishes. However, descriptive information on reproductive behaviour, early developments and life history pathways of Amphiprion ocellaris are scarce. In this study, 7 pairs of A. ocellaris having size 89 to 100 mm (presumptive females) and 40 to 60 mm (presumptive males) were developed through pair formation to generate information on breeding and spawning behaviour, egg morphology, and embryonic, larval, juvenile and adult developments. The spawning was found to be year-round with reproductive cycle of 12 to 15 days intervals and laid 300 to 1000 capsule shaped and adhesive type eggs. The eggs were 1.5-3.0 mm in length and 0.8-1.84 mm in width containing multiple oil globules of varying size and were pale yellow or white for initial two days, turned to black on 3rd to 5th day and silvery on 6th to 7th day of incubation

केरल में सीबास लाटस कालकारिफर का कारीगरी पिंजरा पालन

कृपया पूरा लेखा पढ

Rescue of stranded Hawksbill turtle in Kollam, Kerala

On 27th  March, 2019, fisher folks of Kakkathoppu, a coastal area of Kollam district in Kerala, India, found a Hawksbill turtle (Eretmochelys imbricata), stranded in the rocky seashore (Fig1). The turtle was live female that weighed approximately 50 kg having a carapace length of 48 cm. According to the local fishermen, the turtle was unable to swim back to sea due to ruptured carapace and fatigued condition. On primary evaluation, barnacles were observed to be covering a part of its body and the carapace as well as head region were found exposed to sunburn

Record sized Alepes vari and Nematalosa nasus

The herring scad, Alepes vari is a common pelagic fish species in the family carangidae. The species is the largest fish of the scad genus Alepes and maximum length so far recorded all over the world oceans is 560 mm TL (Froese & Pauly, FishBase 2016, http://www.fishbase.org.). During a regular field visit, an unusually large specimen of A. vari was recorded from Kalamukku Landing Centre, Kerala on 25th May, 2016. This was a male individual measuring 600 mm in total length (TL) and weighing 1.6 kg (Fig. 1)and was caught by hook and line. Young ones occasionally occur in pelagic trawls and larger ones rarely occur in gill net and hook and line catches

Whale shark landed in Sakthikulangara Fisheries Harbour

An immature female whale shark Rhincodon typus accidently caught by a multiday trawler on 19th August 2019 was landed on the same day at Sakthikulangara Fisheries Harbour (Fig. 1) Listed as an endangered species by International Union for Conservation of Natural Resources, locally the shark is known as ‘pullisravu.’ The whaleshark measured 265cm and weighed approximately 250kg. As there was no buyer for this species which is protected under the Indian Wildlife (Protection) Act, 1972, the carcass was discarded into the sea

Breeding and seed production of Clown fishes under captivity

Ornamental fish production for the aquarium industry is a multimillion dollar industry in the world. Aquarium keeping is amongst the most popular of hobbies with millions of enthusiasts worldwide. Although most fish kept in aquariums are from freshwater, the acquisition of marine ornamental fish has greatly increased in recent years and is also popularized through children’s movies by starring charismatic colourful fishes and other creatures. Recent advances in fish husbandry and aquarium gadgets and technology have further facilitated the hobby. In India, marine ornamental fish trade is an emerging area during the last two decades and the industry is further advancing. Along with it ancillary business such as aquarium making, aquarium plants and live feed production, grow- out culture etc. are also flourishing

Sphyraena arabiansis a new species of barracuda (Family: Sphyraenidae) from the south-west coast of India

A new species of barracuda Sphyraena arabiansis is described based on specimens collected from the eastern Arabian Sea off Kerala coast, India. The new species is morphologically similar to Sphyraena barracuda and both were so far considered as one species. Characters such as more and relatively small cycloid scales, 118-122 along lateral line, 11 along vertical axis above lateral line at first dorsal and 13 below the lateral line at anal origin; broad, round spoon shaped maxilla ending vertically below, before the anterior margin of the eye, narrow inter orbital area (4.2-5.13 in head length) and more prominent pointed paired central lobes of caudal fin make Sphyraena arabiansis sp. nov. clearly distinct from S. barracuda. Other distinguishing characters are prominent curve of the lateral line before the origin of first dorsal fin, absence of black spots on the body, white branchiostegal membrane, broad, thick and inwardly curved otoliths with round, blunt posterior end and an elongated, pointed anterior upper lobe. The mitochondrial Cytochrome oxidase C subunit 1 (COI) gene sequence studies revealed that the new species has distinct genetic divergence from S. barracuda and other species of the family occurring in the area

Indiscriminate exploitation of juvenile black pomfret by ring seines along Kerala coast

Black pomfret, Parastromateus niger is an highly esteemed food fish with a very good demand in local and export markets. Unusual heavy landings of juvenile black pomfret was observed at the Kalamukku Landing Centre on 22nd and 23rd August 2016. On 22nd August, a big shoal of about 2 tonnes (t) of juvenile black pomfret was caught by one mechanised inboard (280 HP engine) ring seine unit. Similarly, on 23rd August about 1.25 t of juvenile black pomfret was landed by two mechanised inboard ring seine units with 440 HP engine power