The Aquatic Commons is a thematic digital repository covering the natural marine, estuarine /brackish and fresh water environments . It includes all aspects of the science, technology, management and conservation of these environments, their organisms and resources, and the economic, sociological and legal aspects.
Subject = Biology
Mostrando recursos 1 - 20 de 5,325
Effect of temperature on the oxygen consumption of Penaeus monodon postlarvae - Catedral, F.F.; Sayson, R.
The study aimed to determine the oxygen consumption of P. monodon postlarvae at different temperatures. Results suggest dependence of oxygen consumption on both weight of postlarvae and temperature. The relationships appear linear at the temperature range examined. Temperature dependence of oxygen consumption suggests that oxygen requirement (and metabolism) increases with temperature.
Bioenergetics of the freshwater prosobranch Idiopoma angularis Muller in Laguna de Bay - Baluyut, Elvira A.
This study was made as an attempt to investigate some of the ecological aspects of the freshwater snail Idiopoma angularis Muller in a modern framework of energy flow and mathematical models. It offers the first investigation of respiration (as related to temperature and body size), production (growth), and excretion in the prosobranch I. angularis in Laguna Lake.
Incidence and low temperature survival of Salmonella in fishery products - Gopalakrishna Iyer, T.S.; Shrivastava, K.P.
Salmonella was isolated from 12% of PD shrimps, 10% of HL shrimps, 14% of PUD shrimps, 17% of lobsters, 14% of cuttle fish, 25% of cat fish and 20% of seer fish (all frozen) tested. One percent of the fish meal, 4% of dried non-penaeid prawn and 23% of sea beach sand showed incidence of the organism. Salmonella was also isolated from 2 and 4% of the swab samples of utensil surfaces and the floor surface of the processing hall respectively as well as from 1% of the process water tested. All the serotypes of Salmonella tested were resistant to...
Length-weight relationship in Nandus nandus (Hamilton) (Perciformes-Teleostei) - John, K.C.; Balakrishnan Nair, N.
Length-weight relationship of the freshwater fish of Pamba River, Nandus nandus (Ham) has been worked out. The results showed that the slope values and elevations were not significant and hence a combined regression equation has been calculated for both the sexes (Log W=2.4130 Log L -0.3306). The’t’ test analyses were conducted and found that the growth departs significantly from the isometric growth. Thus the formula W=aL super(n) has to be applied in calculating the length-weight relationship of this species.
Preliminary studies on predicting the setting season of oysters for the benefit of shellfish farmers - Young, A.L.; Gargantiel, E.; Traviña, R.
Preliminary findings from a spatfall forecasting programme initiated in April 1981 at Himamaylan River, Negros Occidental are presented. Two main activities are involved: 1) monitoring of daily counts of oyster larvae in the plankton; and 2) monitoring of actual setting of oysters on standardized collectors put in the vicinity of oyster farm sites. Findings indicate that when the count of mature larvae exceeds 5 per 100 ml sample and persists for at least 3 days, spat may be expected to occur shortly afterwards.
Acute toxicity of un-ionized ammonia to milkfish (Chanos chanos) fingerlings - Cruz, E.R.
The acute toxicity of un-ionized ammonia to milkfish (Chanos chanos) fingerlings was determined using a static bioassay system. Median lethal concentrations found show that milkfish fingerlings have a high tolerance to ammonia and it is unlikely that levels as high as those employed for the acute exposure would be found to occur under natural conditions. Although the threat of acute toxicological effects induced by ammonia are remote, such conditions might be encountered in stressed natural environments or in heavily loaded aquaculture systems.
Effects of exogenous hormone injections on milt consistency in newly caught, wild milkfish - Juario, J.V.; Quinitio, G.F.; Banno, J.; Natividad, M.
A study was conducted to determine the effects of single injections of human chorionic gonadotropin (HCG) and Durandron Forte 250 on sperm motility, vitality and density and also on the consistency of milt in newly caught, wild, mature milkfish (Chanos chanos). In contrast to HCG, single injections of Durandron Forte 250 were effective not only in inducing spermiation but also in maintaining newly caught mature males in good running condition for a maximum of 7 days, despite daily handling and collection of approximately 3ml milt.
Growth and survival of Penaeus monodon Fabricius zoeae on different diatom feeds - Suñaz, F.P.
A study was undertaken to determine the most suitable food for Penaeus monodon zoea out of mixed diatoms, Skeletonema costatum, Chaetoceros calcitrans and C. gracilis. Results indicate that mixed diatoms and C. gracilis are the better food. Addition of zooplankton, e.g.rotifers, is also recommended as early as Z3 since the larvae start to be omnivorous at this stage.
Fundamental study on the behavior of milkfish fry for the evaluation of the efficiency of traditional fry collecting gears in the Philippines - Kawamura, Gunzo; Hara, Shiro; Bagarinao, Teodora
The response of Chanos chanos fry to moving and stationary nets of different mesh size and colour, underwater visibility of the nets and water filtration were studied. Results indicate that milkfish fry may be driven by nets of mesh size larger than that presently used; larger mesh size decreases the net resistance in the water so that collectors may move the equipment easily. The large mesh nets should be of a dark colour, preferably black for effective driving; bowever white mosquito net is best for the core end, since the fry are more easily visible on a white background.
Effect of substrate types on fecundity and nauplii production of ablated Penaeus monodon Fabricius - Pudadera, Rosario; Primavera, Jurgenne; Borlongan, Emeterio
Experiments were undertaken to assess the survival, spawning, fecundity and nauplii production of ablated P. monodon females reared in flow-through broodstock tanks with white coralline and black sand substrate for 62 days. The similar trend observed in mortality rates in both substrates suggests that variation in substrate material for broodstock tanks is not a likely cause of prawn mortality. There were also no significant differences observed between rematurtion rates, i.e. number of spawnings, under the different treatments. Singnificantly higher nauplii production were observed in females in tanks with white substrates. At present, the land-based broodstock tanks in SEAFDEC utilize white...
Morphometric measurements as an index for estimating yield of meat in shell fishes, 2. Mussel (Perna viridis) and clam (villorita cyprinoides) - George, C.; Unnithan, G.R.; Gopakumar, K.
Observations (76 nos) on height-length and whole weight-meat weight relations of mussels (Perna viridis), both wild and cultured were made. From the length of mussel the height can be worked out by the equations (logarithmic scale), 1. y = 0.360+0.988 x for wild; 2. y = 0.334+1.011 x for cultured, where x is the length (cm) and y is the height (cms). So also to any height the corresponding meat weight can be obtained by the regression equation. log w=-0.8178+1.9769 log H for wild variety (1) log w=-1.3049+2.8385 log H for culture-variety (2) where w is the meat weight (g)...
The bacteriology of oil sardine (Sardinella longiceps) and mackerel (Rastrelliger kanagurta) from tropical waters off Cochin. 2. Qualitative aspects - Surendran, P.K.; Gopakumar, K.
80% of the flora of skin, gills and intestines of oil sardine and mackerel at isolation temperature 28 ± 2°C consisted of Gram negative asporogenous rods or cocci, belonging to the genera Vibrio, Pseudomonas, Moraxella, Acinetobacter and Flavobacteria/Cytophaga. Nearly 10% of the flora was constituted by Gram positives, Micrococcus and Arthrobacter. Incubation temperature of 36 ± 1°C recovered more Vibrio spp. and Gram positives, while at lower temperatures of 8 ± 1°C and 1 ± 1°C, more Pseudomonas, Acinetobacter and Moraxella spp. were recovered. Significant changes with respect to season were observed in the relative distribution of different genera.
Studies on lantern fish (Benthosema pterotum) 2. Nutritional evaluation - Lekshmy Nair, A.; James, M.A.; Mathew, P.T.; Gopakumar, K.
Various methods for processing and utilization of lantern fish (Benthosema pterotum) are reported. Nutritional evaluation of fish meal and fish hydrolysate from lantern fish has been carried out. Growth rate and PER of lantern fish meal are similar and better than that of the reference protein, casein. Lantern fish meal can therefore be extensively used for the formulation of poultry, fish and other animal feeds as a good protein supplement with beneficial effects.
Studies on mollusca of Saurashtra coast - II. (Pelecypoda) - Sarvaiya, R.T.
The paper deals with the proximate composition of Crassostrea graphoides, C. cucullata, Placenta placenta, Pinna vexillum, P. bicolor, P. atropurpurea, Solen truncatus and Pitar erycina. Seasonal variations in water, protein, salt and ash in the meat of C. graphoides, C. cucullata and P. placenta are reported. Percentage of meat is high in S. truncatus and low in C. graphoides, C. cucullata and P. erycina. Most of these species contain higher moisture than gastropods
Studies on mollusca of Saurashtra coast - I. (Amphineura and Gastropoda) - Sarvaiya, R.T.
Proximate composition of 19 species of marine Gastropoda and one of marine Amphineura have been studied. Seasonal variations in proximate composition of the meat of gastropods, Thais rugosa (Born), are reported. Majority of the gastropod species have high protein and ash contents.