1,104 research outputs found
Evaluation of acute toxicity of copper cyanide to freshwater fish, Catla catla (Hamilton)
The acute toxicity of copper cyanide to the juveniles of Indian major carp Catla catla
(2±0.5 cm) was evaluated under static renewal conditions. The concentrations of
copper cyanide that killed 50% of the carp fingerlings within 96-h (96-h LC50) was
found to be 0.76 ± 0.04 mg/L. Fishes exhibited abnormal swimming activity, followed
by frequent gill flapping, loss of equilibrium, gulping of air, hyperactivity, convolutions.
The respiratory rate of the fish got severely affected (-63.41%± 0.002) when exposed
to copper cyanide.
Vibrio ponticus, a new pathogen of cultured cobia
Most of the members of the family Vibrionaceae
are natural inhabitants of marine and estuarine
ecosystem and several of them are pathogens in
cultured aquatic organisms. Vibriosis caused by
some pathogenic Vibrio spp., can cause huge
mortality in marine fish culture systems.
Intermittent mortality with haemorrhagic lesions on
the fin, body surface, and head, exophthalmia
(Fig.1) and stopping of feeding activity were noticed
in cobia (25±5 cm length; 17±4 g weight) reared in
sea cages off Polem, Goa during June 2015. The
clinical signs lasted for a week with a total mortality
of 12%. Isolation of bacteria aseptically from liver
and kidney was done
Respiratory distress and Behavioural Anomalies of Indian major carp, Labeo rohita (Hamilton) Exposed to Sodium Cyanide
Sodium cyanide, is highly contaminating aquatic ecosystems as a toxic pollutant, was investigated in the present study for acute toxicity on freshwater fish Labeo rohita. The toxicity tests were conducted by static renewal bioassay method on the juveniles of fish was evaluated. The LC50 value of sodium cyanide to Labeo rohita was found out to be 320 µg/L. One third (106 µg/L) and one fifth (64 µg/L) of the LC50 value was selected for sublethal studies. Behavioural patterns and oxygen consumption were observed in both (1/3rd and 1/5th) sublethal concentrations (1, 5, 10 and 15 days). Sodium cyanide is highly toxic to the animal tested. Fish behaved irregular, erratic, and dartic movements, by followed hyperexcitability, loss of balance, finally settled to the bottom of the test chamber. A decrease in oxygen consumption was observed in 1/3rd (11.62% and -4.52%) and 1/5th (9.11% and -2.82%) sublethal concentrations. Fish under sublethal concentration were found to be under stress but not fatal
Nursery rearing of Asian Seabass
Lates calcarifer species is widely distributed in
the tropical and subtropical areas of the western Pacific and Indian
ocean including Australia, Southeast Asia, the Philippines and
countries bordering the Arabian sea. Seabass spend most of their
life in a lagoon which connects to the sea. They spend two to
three more years in estuarine areas until they mature, then migrate
to the sea water around the mouth of a river or lagoon for
spawning. Larvae and juveniles live in the sea grass bed in coastal
areas for about six months, attaining a size of about 2 to 5 inches.
The fish migrate to freshwater when they grow bigger
Impact of copper cyanide on the key metabolic enzymes of freshwater fish Catla catla (Hamilton)
Short term toxicity experiments were conducted to study the effect of metal cyanide complex (copper cyanide) on the key metabolic enzymes viz., lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), glucose-6 phosphate dehydrogenase (G6PDH), aspartate amino transferase (AST) alanine amino transferase (ALT), acid phosphatase (AcP) and alkaline phosphatase (ALP) activity in Catla catla juveniles. A total of 60 fingerlings were (2±0.5 cm; 1.5±0.2 g) exposed to two sublethal concentrations (0.253 and 0.152 mg/L) for a period of 15 days. Copper cyanide had significant (P> 0.05) effect on the key metabolic enzymes, the highest activities were observed in the group exposed to 0.253 mg/L. Results suggest that metal cyanide complex significantly altered enzyme activities of fish in both the sublethal concentrations
Stranding of spinner dolphin, Stenella longirostris (Gray, 1828) at Karwar, Karnataka
A spinner dolphin, Stenella longirostris , locally
called ‘handi meenu’ was noticed in dead condition
floating near the marine cage farm of CMFRI, Karwar,
approximately 600 m away, from sea shore of
Aligadda village in the evening hours on 31st August
2012. The specimen was an adult female of 175 cm
total length and 55 kg weight. The animal had a small
injury near its left eye probably as a result of getting
entangled in fishing nets or got injured in purse-seine
operation which resulted in its death
Cobia culture in low volume cages in coastal waters of Uttara Kannada, Karnataka
Cobia, Rachycentron canadum is a marine finfish globally
favoured for aquaculture. In India, cage culture of
cobia was first reported by ICAR-CMFRI in 2013 with
better growth rate recorded under conditions of higher
salinities (Philipose et al.2013). The present report is
on the growth and production of cobia, Rachycentron
canadum in Gangavali estuary (14o 61’ 225’’ N and
74 o35’726’’E) of coastal Karnataka during the period
2018-19
Note on the ocean sunfish, Mola mola (Linnaeus, 1758) landed at Karwar, west coast of India
The spine tail devil ray Mobula japanica (Muller
& Henle, 1841) is a large zooplanktivorous ray circumglobally
distributed within tropical to warm
temperate waters. This species belong to the family
Mobulidae. In the genus Mobula, the mouth is located
ventrally and is currently represented by nine
recognised species
Incidence of whale strandings in Uttara Kannada, Karnataka
Two instances of the whale strandings were observed in the Uttar Kannada district of Karnataka recently. The first one occurred on 06.05.2017 at Mungodlu, Kumta and the second at Karwar on 18.02.2018. The whale stranded at Mungodlu, near Vannalli village of Kumta Taluk, Uttara Kannada district, Karnataka (14° 26' 034" N and 74° 23' 005" E) was washed ashore in highly decayed condition with its dorsal portion upside down and species could not be identified. The total length of the whale was approximately 9 metres. The vertebrae were found exposed in the beach and a few numbers were collected and preserved in the museum of Karwar Research Centre of ICAR- CMFR
Foreign objects observed in the stomach of a cobia (Rachycentron canadum) reared in sea cage at Karwar
Revival of short neck clam Paphia malabarica Chemnitz, 1782 In Kali
estuary, Karwar, Karnatak
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