Studies on the Tetraclitidae (Cirripedia: Balanomorpha); new species of Tetraclita from the Red Sea

The tetraclitid fauna at Elat, Israel, on the Gulf of Aqaba, Red Sea, consists of three morphologically distinct species. Tetraclita rufotincta Pilsbry, 1916 was reported previously from this region and may have been confounded with T. achituvi n.sp. and T. barnesorum n.sp. Although these species occur sympatrically, according to previous studies, and recent observations, they apparently occupy different levels in the narrow intertidal zone (=50 cm) of this area. Cirral morphology suggests that each differs in the manner by which they capture and manipulate prey. Little is known about the occurrence of these new species elsewhere in the Red Sea and adjoining Arabian Sea.

A method of immersion of panels for ecological studies on marine fouling and boring organisms

The importance of studies on the biology of marine foulers and borers needs no emphasis since they cause damage to submerged wooden structures resulting in considerable economic loss. In order to study their occurrence, settlement and to assess the rate of destruction to timber, several immersion techniques using iron racks, cages and rafts have been adopted. On the east and west coasts of India, at the Marine Centres of Forest Research Institute (Waltair, Madras, Cohin and Bombay) investigations have so far been carried out employing the first two methods.

Water budgeting studies on the hatchery and nursery rearing practices for the common carp, Cyprinus carpio (Linnaeus, 1758)

Aquaculture systems are an integral element of rural development and therefore should be environment friendly as well as socially and economically designed. From the economic standpoint, one of the major constraints for the development of sustainable aquaculture includes externalities generated by competition in access to a limited resource. This study was conducted as an investigation into the water requirement for the hatchery and nursery production phases of common carp, Cyprinus carpio (Linnaeus, 1758) at the Maharashtra State Fish Seed Farm at Khopoli in Raigad Dist. of Maharashtra during the winter months from November to February. The water budgeting study involves the quantification of water used in every stage of production in hatchery and nursery systems and aimed at becoming a foundation for the minimization of water during production without affecting the yield; thereby conserving water and upholding the theme of sustainable aquaculture. The total water used in a single operation cycle was estimated to be 11,25,040 L [sic]. Out of the total water consumed, 4.74% water was used in the pre-operational management steps, 4.48% was consumed during breeding, 62.72% was consumed in the hatching phase, 21.50% was used for hatchery rearing and 6.56% was consumed during conditioning. In the nursery ponds, the water gain was primarily the regulated inflow coming through the irrigation channel. The total quantum of water used in the nursery rearing was 31,60,800 L [sic]. The initial filling and regulated inflow formed 42.60% and 57.40% respectively of water gain, while evaporation, seepage and discharge contributed 20.71%, 36.46% and 42.82% respectively to the water loss. The total water expended for the entire operation was 1,21,61,120 L [sic]. Water expense occurred to produce a single spawn in the hatchery system was calculated and found to be 0.56 L while the water expended to produce one fry was calculated as 4.86 L. The study fulfills the hydrological equation described by Winter (1981) and Boyd (1985). It also validates the water budget simulation model that can be used for forecasting water requirements for aquaculture ponds (Nath and Bolte, 1998).

Studies on diversity of Hara's Laft-Khamir and Sout Beaches of the Gheshm polychaete

One of the most important marine ecologic phenomenon , is the study of animal community among the bed or benthic fauna. Macrobenthoses are the graet part of the benthic faune , that are more biomasses than meiofauna and microfauna. To study polychaetes diversity of Mangroves, located in Khoore-Khooran , sampling was conducted on a bimonthly and carried out from December 2001 to October 2002. Bottom samples were collected by Van Veen grab (0.025 m2)at 6 station from 2 transect Insitu measurement of temperature , pH , Do and salinity were done . Atotal of polychaetes werw identified within study 32 Family and 43 Genus . Cirriphormia and Nephtys were the most dominant genus in the studies . The range fomumerical abundance of polychaets was between 3006 per m2 in the station A3 to 559individual per mein the station A1 and the variation was done to different bottom , texture the variable environment conditions govrtneng the different parts of each creeks as well as within creeks . Application of diversity indices (Shannon H') on the dominant polychates assambladges has higher H' in the Azar and lower 1-1/ in the Mehr . and the stations B3 has the highest H' and the station A2 has the lowest H' Application of diversity and Richness, Evennes were studied and showed that the station A3 has the lowest evenness and the most individual , and station A1 has the middle pollution.

Studies on distribution, diversity and production of macrobenthic fauna in the Chahbahar Bay

The population density, distribution, diversity and secondry production of macrobenthic fauna of the inner Chahbahar Bay were studied through bi-monthly sampling from April 1995 to March 1996. Samples were collected from water near the bottom and sediment at 14 stations inside the Bay and one reference station located outside at the entrance to the Bay. The environmental parameters Such as temperature, water depth, salinity, pH and dissolved oxygen as well as percentage silt-clay and total organic matter of the sediment were measured. The faunal population density and their distribution is discussed in relation to the environmental changes. results obtained indicated both spatial and temporal heterogeneity in faunal distribution of the Chahbahar Bay. The total of 18 groups of macrofauna were identified in all samples. Amphipods formed the dominant group (21%) followed by polychaetes (19%), gastropods (15.7%) bivalves (10.6%) and all other groups (33.7%). Seasonal changes in faunal density is shown in relation to Indian Ocean southwest monsoon,the result of which indicated lower population density during monsoon (June to September) than that of the premonsoon (February to May) and post monsoon (October to January) periods. The numerical abundance of macrobenthos varied from 10260.m2 before monsoon to 5190 m2 during monsoon season. Three dominant groups of macrofauna including polychaetes, gastropods, and bivalves were identified in all collected samples. Indices of diversity, richness and evenness were calculated for these three dominant groups. The Shannon-Weaver information index was used to describe the spatially and temporally variation in diversity of these three major faunal groups. The results exhibited lower faunal diversity during monsoon period. The annual production of two dominant macrofauna species including a species of bivalve, Nuculana acuta and a species of Cephalochordata, Branchiostoma lanceolatum were measured by using age group determination. Furthermore the mean biomass and total annual production of macrobenthic fauna were estimated for the whole studied area. The potential yield of demersal fishery resources (fish and crustacean) then estimated and worked out to be 15360 tons/year asuming 10% ecological efficiency of hypothetical pyramid from 3rd to 4th marine trophic level. Accordingly the annual exploitable demersal fishery resources for the entire Chahbahar Bay was estimated to be 7600 to 8500 tons/year by taking 50 to 55% of the total estimated potential in to account.

Studies on induced breeding of Clarias gariepinus (Burchell, 1822) in hapa pens

Induced breeding of Clarias gariepinus was conducted monthly in hapa pens, set up in Otamiri river for nineteen months (June 1993 - December 1994). Results of natural fertilization were unsatisfactory as few eggs were fertilized. Mean relative fecundity, percentage fertilization, percentage hatching and percentage fry survival were: 15.86 ± 1.95 x 10', 18.92 ± 5.28%, 13.50 ± 3.8% and 6.42 ± 0.72%. Results from artificial fertilization were as follows: Mean relative fecundity, 13.80 ± 2.85 x 10', percentage fertilization, 81.91 ± 2.28%, percentage hatching, 86.10 ± 2.46% and percentage fry survival, 21.40 ± 1.89% respectively. The success of artificial fertilization depended largely on the latency period of 9-11 hours and this suggests that induced breeding in pens is feasible. The poor results from natural fertilization were attributed to lack of adequate substrate for the male fish to display courtship and subsequent fertilization of eggs.