Long-term monitoring of habitats and reef fish found inside and outside the U.S. Virgin Islands Coral Reef National Monument: a comparative assessment

The primary objective of this study was to assess the efficacy of the Virgin Islands Coral Reef National Monument (VICR), a marine protected area in St John, US Virgin Islands. Surveys of habitat and fishes inside and outside of VICR were conducted in 2003-2008. Areas outside the VICR had significantly more scleractinian corals, greater habitat complexity, and greater species richness and density of reef fishes than areas inside., Areas inside and outside the VICR exhibited significant decreases in percent scleractinian coral coverage over the study period. A contrasting trend of increasing macroalgal cover was also observed. No clear effect of the severe 2005 coral bleaching event was observed suggesting other causal factors. No obvious trends in the fish community were observed across the study period. The significant decline in habitat condition, coupled with the initial incorporation of some of the more degraded reefs into the marine protected area may result in a longer time period necessary to detect positive changes in the St. John coral reef ecosystem and associated reef fish abundance and community structure.

Liver genomic responses to ciguatoxin: evidence for activation of Phase I and Phase II detoxification pathways following an acute hypothermic response in mice

Ciguatoxins (CTX) are polyether neurotoxins that target voltage-gated sodium channels and are responsible for ciguatera, the most common fish-borne food poisoning in humans. This study characterizes the global transcriptional response of mouse liver to a symptomatic dose (0.26 ng/g) of the highly potent Pacific ciguatoxin-1 (P-CTX-1). At 1 h post-exposure 2.4% of features on a 44K whole genome array were differentially expressed (p ≤ 0.0001), increasing to 5.2% at 4 h and decreasing to 1.4% by 24 h post-CTX exposure. Data were filtered (|fold change| ≥ 1.5 and p ≤ 0.0001 in at least one time point) and a trend set of 1550 genes were used for further analysis. Early gene expression was likely influenced prominently by an acute 4°C decline in core body temperature by 1 h, which resolved by 8 h following exposure. An initial downregulation of 32 different solute carriers, many involved in sodium transport, was observed. Differential gene expression in pathways involving eicosanoid biosynthesis and cholesterol homeostasis was also noted. Cytochrome P450s (Cyps) were of particular interest due to their role in xenobiotic metabolism. Twenty-seven genes, mostly members of Cyp2 and Cyp4 families, showed significant changes in expression. Many Cyps underwent an initial downregulation at 1 h but were quickly and strongly upregulated at 4 and 24 h post-exposure. In addition to Cyps, increases in several glutathione S-transferases were observed, an indication that both phase I and phase II metabolic reactions are involved in the hepatic response to CTX in mice.

Hybridization between two serranids, the coney (Cephalopholis fulva) and the creole-fish (Paranthias furcifer), at Bermuda

Intergeneric hybridization between the epinepheline serranids Cephalopholis fulva and Paranthias furcifer in waters off Bermuda was investigated by using morphological and molecular characters. Putative hybrids, as well as members of each presumed parent species, were analyzed for 44 morphological characters and screened for genetic variation at 16 nuclear allozyme loci, two nuclear (n)DNA loci, and three mitochondrial (mt)DNA gene regions. Four of 16 allozyme loci, creatine kinase (CK-B*), fumarase (FH*), isocitrate dehydrogenase (ICDH-S*), and lactate dehydrogenase (LDH-B*), were unique in C. fulva and P. furcifer. Restriction fragments of two nuclear DNA intron regions, an actin gene intron and the second intron in the S7 ribosomal protein gene, also exhibited consistent differences between the two presumed parent species. Restriction fragments of three mtDNA regions—ND4, ATPase 6, and 12S/16S ribosomal RNA—were analyzed to identify maternal parentage of putative hybrids. Both morphological data and nuclear genetic data were found to be consistent with the hypothesis that the putative hybrids were the result of interbreeding between C. fulva and P. furcifer. Mean values of 38 morphological characters were different between presumed parent species, and putative hybrids were intermediate to presumed parent species for 33 of these characters. A principal component analysis of the morphological and meristic data was also consistent with hybridization between C. fulva and P. furcifer. Thirteen of 15 putative hybrids were heterozygous at all diagnostic nuclear loci, consistent with F1 hybrids. Two putative hybrids were identified as post-F1 hybrids based on homozygosity at one nuclear locus each. Mitochondrial DNA analysis showed that the maternal parent of all putative hybrid individuals was C. fulva. A survey of nuclear and mitochondrial loci of 57 C. fulva and 37 P. furcifer from Bermuda revealed no evidence of introgression between the parent species mediated by hybridization.

A comparative study on the hatching of common carp eggs in hapa and hatchery (model CIFE D-80)

Common carp (Cyprinus carpio) eggs were incubated to study the efficiency of hatching in hapa and hatchery. During incubation the recorded temperature was 21-28 degree C and 20-31 degree C, dissolved oxygen 6-9 ppm. and 3-5 ppm., total alkalinity 180-250 ppm. and 28-62 ppm. respectively in the hatchery (model C.I.F.E. D-80) and hapa. CO sub(2) was totally absent in the hatchery, but recorded 3-10 ppm. in the hapa. The flow of water was maintained at 1.25 l/minute/jar in the hatchery. Under the above environmental conditions the eggs hatched in 42-51 hrs. in the hatchery and 61-81 hrs. in the hapa from egg to spawn thereby establishing the hatchery to be a better hatching system for carp eggs.

A comparative note on the modus operandii of reservoir development in Republic of China and India

Principles adopted by China for the development of reservoir fisheries are discussed. Production of some of reservoirs of China with that of India is compared. The reasons for obtaining higher production in China have been recognised as: emphasis on utilization of all resources for food production; direct feeding; use of selected varieties of fast growing carps; keeping 15 pigs per hectare of water area for application of pig void and application of manure; production of fingerlings at the reservoir sites enclaving coves and bays; grading and removing obstructions from bottom; rational harvesting and stocking and improvement of reservoir shore areas as a whole. Some of these measures which could be implemented in Indian conditions are briefly described.

Comparative toxicity of some detergents on an estuarine fish, Ambassis commersonii

The comparative toxicity was evaluated using four detergents, viz, linear alkylbenzene sulfonate (LAS), branched alkylbenzene sulfonate (BAS), sodium sulfonate (SS) and alfa-olefin sulfonate (AOS) on an estuarine fish, Ambassis commersonii, abundant in Kali estuarine system. Standard toxicity bioassay method was followed as per APHA (1980). AOS concentration in "Mega" soap was determined by the standard MBAS method described in APHA (1980). The results indicate that LAS was the most toxic detergent to fish relative to the other types and the other of toxicity was LAS > AOS > SS > BAS. A significant correlation was seen between observed and calculated mortalities for all the detergents. Some behavioural responses of fishes to all detergents were also observed.

Comparative haemagglutinic activity in the species of Caulerpa and Ulva (Chlorophyta) of Karachi coast

Aquous extracts of 24 species of green seaweeds, 13 of Caulerpa Lamour and 11 of Ulva Linn, were collected from the coastal areas near Karachi, Pakistan and tested for haemagglutination against human erythrocytes of blood groups A,B,AB and O and compared. All the species of Caulerpa and seven of Ulva exhibited a positive activity, the former genus (a member of Bryopsidophyceae) appeared to possess more phycohaemagglutinins than the latter (a member of Ulvophyceae). The haemagglutinic activity proved to be quite helpful in the distinction of various species of both the genera.

On the comparative efficiency of conventional and bulged belly fish trawls

To ensure a greater vertical opening while under tow, a trawl net with a bulged belly was made and compared with a conventional design under actual fishing conditions. It was found that the new design landed 31.8% more fish. Since the percentage lateral spread was relatively less for the bulged belly net, it was inferred that this net had higher head line height, while under operation and this was further substantiated by a greater catch of off—bottom fishes. Further, half the quantity of twine can be saved by changing the conventional trawl to that of bulged belly type.

Comparative fishing ability and economic efficiency of mechanised trawlers operating along the Kerala coast

This study was undertaken with a view to finding out the comparative fishing ability and economic performance of different fishing vessel sizes 9.15m (30'), 9.76m (32') and 10.97m (36') designed by the Central Institute of Fisheries Technology and operating along the Kerala coast. Data were collected from selected vessels of these sizes for four consecutive fishing seasons from 1964-65 to 1967-68. The catch/unit effort and total effort per year for the 10.97m (36') vessels were much better than those for the 9.76m (32') vessels. The yearly landings and the crew remuneration for the former were about twice those of the 9.76m (32') vessels. The economic efficiency of the 10.97m (36') vessels was also much better. The decline in landings per year in both size groups was more due to the reduction in the effort per year than the decline in catch/unit effort.

Comparative studies on growth of fry of GIFT and Existing strain of Nile tilapia (Oreochromis niloticus L.)

Comparative study on growth of fry in nursery system of Genetically Improved Farmed Tilapia (GIFT) and Existing strain of Nile tilapia (Oreochromis niloticus) was performed. The trials were conducted in a series of hapa for two months. The initial mean weight of GIFT and Existing strains of tilapia were 1.03 and 1.12g, respectively and the stocking density for both the strains was maintained at 150/m³. Fishes were fed with supplementary feed 31.29% of protein level. After two months the final cumulative mean weight of GIFT and Existing strain were observed to be 8.38 and 5.51g, respectively. The net gain for weight of GIFT and existing strain were estimated to be 666% and 368% and the mean survival were 95.75% and 81.25%, respectively. The GIFT strain showed significantly (P<0.05) higher net gain in growth in weight and also higher (P<0.01) survival than that of existing strain.

Results of comparative fishing trials with rectangular flat and rectangular curved otter boards

The communication deals with the results of comparative fishing operations conducted to study the effectiveness of rectangular flat and rectangular curved otter boards. Based on the analysis of data gathered during the course of actual field trials, following conclusions have been drawn: the average catch per hour of trawling was more by 22 kg during attachment of rectangular curved otter boards. The average horizontal spread between rectangular curved otter boards in action was more by 13% and works out to 50% of the head-rope length of the net including sweeps. The towing resistance of the gear with horizontally curved otter boards was more by 10%.

Comparative fishing experiments with two trawl designs used in the inshore waters off Kakinada (Andhra Pradesh)

The importance of small trawlers for the economic exploitation of the inshore demersal fisheries is well recognized and accordingly mechanized boats of sizes 30' and 32' fitted with engines of h.p. ranging from 30 to 45 came into existence particularly at Kakinada. The need to work out the most suitable trawling gear for these classes of boats becomes imperative and as an appurtenance to this, comparative fishing experiments were attempted with different trawls. In the present communication certain observations made on the relative catch efficiency of two different trawl nets used in combination with two different shaped otter boards are given.

Comparative studies on the canning properties of pomfrets and hilsa

Fresh silver pomfret, black pomfret and hilsa were canned at absolutely fresh and iced conditions and the qualities of the final products were studied comparatively in relation to the initial quality of the raw materials. Under identical conditions a maximum quantity of cook-drip and nitrogen contents were found to be lost in black pomfret and minimum in hilsa. Silver pomfret and black pomfret iced for 3 days gave fairly good products on canning while hilsa came out only as a satisfactory product on canning after the same ice storage period of the raw material.