Reproductive Biology and Spawning Periodicity of Endeavour Shrimps Metapenaeus endeavouri (Schmitt, 1926) and Metapenaeus ensis (de Haan, 1850) from a Central Queensland (Australia) Fishery

Metapenaeus endeavouri and M. ensis from coastal trawl fishing grounds off central Queensland, Australia, have marked seasonal reproductive cycles. Female M. endeavouri grew to a larger size than female M. ensis and occurred over a wider range of sites and depths. Although M. ensis was geographically restricted in distribution to only the shallowest sites it was highly abundant. Mating activity in these open thelycum species, indicated by the presence or absence of a spermatophore, was relatively low and highly seasonal compared with closed thelyeum shrimps. Seasonal variation in spermatophore insemination can be used as an independent technique to study spawning periodicity in open thelycum shrimps. Data strongly suggest an inshore movement of M. endeavouri to mature and spawn. This differs from most concepts of Penaeus species life cycles, but is consistent with the estuarine significance in the life cycle of Metapenaeus species. Monthly population fecundity indices suggest summer spawning for both species, which contrasts with the winter spawning of other shrimps from the same multispecies fishery.

Commercially Important Crabs, Shrimps and Lobsters of the North Pacific Ocean

Table of Contents [pdf, 1 Kb] Summary [pdf, 85 Kb] Introduction [pdf, 0.8 Mb] Major Species and Stocks of Crabs in the PICES Region [pdf, 1.23 Mb] Major Species and Stocks of Shrimps in the PICES Region [pdf, 0.5 Mb] Oceanography [pdf, 0.4 Mb] Sampling and Data Analysis [pdf, 0.38 Mb] Acknowledgements [pdf, 0.27 Mb] References [pdf, 0.33 Mb] Appendices [pdf, 0.3 Mb] Plates 1-5 [pdf, 0.95 Mb] (Document contains 83 pages)

Illustrated key to Penaeoid shrimps of commerce in the Americas

The commercially important species of penaeoid shrimps comprise 4 families, 12 genera, and 37 species in the Americas, This key is supported by 49 figures including lateral views of whole shrimps in 10 of the 12 genera and detailed figures of male (petasma) and female (thelycum) genital structures of the species. A glossary of terms used in shrimp taxonomy plus a bibliography of references useful in identifying shrimps are included. (PDF file contains 38 pages.)

Fresh and brackish water shrimps of economic importance in the Niger Delta

In the author’s opinion, extremely little is known of fresh and brackish water species, i.e. those supporting the traditional artisanal fisheries and most likely to include suitable candidates for aquaculture. The immediate purpose of this paper is to document the species which are encountered in artisanal fisheries, give available background information on them relevant to fisheries and aquaculture work, and to provide a means for their identification in the field by nonspecialists. Scope of Coverage the "Niger Delta" in the title reflects the geographical area of the author’s personal experience. For purposes of identification, the scope of the paper is West African for brackish species, and Nigerian for freshwater species

Aquaculture potentials and investment opportunity in shrimps and prawns farming in Nigeria

Some aspects of the aquaculture potentials and investment opportunity in shrimps and prawn farming in Nigeria were overviewed. This paper presents the breeding pattern, spawner availability, culture water-type and properties, feeds and feeding regimes and other factors needed in practical shrimps and prawns culture. The culture systems, water management, larval management, stocking density, feeding strategies and diseases were fully discussed. The investment opportunity available as government plans to boost production of these resources from both artisanal and aquaculture sector was documented. Management strategies needed in practical practices of shrimps and prawns culture were enlisted. Effected efforts from the government were listed in this paper

Synopses of research on shrimps: 1. The common shrimp species of Sierra Leone's coastal waters: their distribution, abundance and size composition

The authors present quantitative information on the shrimp resources of Sierra Leone waters. Four of the nine species present have been studied, of which Paenaeus duorarum notialis is dominant in the fishery. Synoptic surveys were undertaken in June 1977, and March 1978, to determine the abundance of the shrimp stock on the inshore shelf. The temperature-salinity-depth curves for the fishing ground show the existence of three water masses. The majority of fish caught were sciaenids, with some sparids also being taken. Detailed discussion of distribution and abundance of individual species of shrimp is given. The surveys have shown that the Banana Islands are the most productive shrimp grounds in the country, and the authors believe that they can support a viable shrimp industry for several years to come at present rates of exploitation

Chemoreception studies in relation to feeding responses in the marine shrimps H. Milne Edwards (Penaeus indicus) and Miers (Metapenaeus dobsonii)

A study of chemoreception in relation to feeding and other factors involved showed that feeding behavior in shrimps can be triggered by chemical stimuli. However, Penaeus indicus and Metapenaeus dobsoni differ significantly in their chemotactic response to different stimuli.

Remote Camera and Trapping Survey of the Deep-water Shrimps Heterocarpus laevigatus and H. ensifer and the Geryonid Crab Chaceon granulatus in Palau

Time-lapse remote photo-sequences at 73-700 m depth off Palau, Western Caroline Islands, show that the caridean shrimp Heterocarpus laevigatus tends to be a solitary animal, occurring below ~350 m, that gradually accumulates around bait sites over a prolonged period. A smaller speies, H. ensifer, tends to move erratically in swarms, appearing in large numbers in the upper part of its range (<250 m) during the evening crepuscular period and disappearing at dawn. Trapping and photsequence data indicate the depth range of H. ensifer (during daylight) is ~250-550 M, while H. laevigatus ranges from 350 m to at least 800 m, along with the geryonid crab Chaceon granulatus. Combined trapping for Heterocarpus laevigatus and Chaceon granulatus, using a three-chamber box-trap and extended soak times (48-72 hr), may be an appropriate technique for small-scale deep-water fisheries along forereef slopes of Indo-Pacific archipelagoes.

On a rational criterion for assigning batch number to processed products of shrimps

Investigations were conducted to find the variability of processed shrimps with respect to two quality characteristics, namely, the numbers of deteriorated and discoloured pieces. Samples were collected for three days from two arbitrarily selected processing factories from Cochin at the pre-freezing stages. Results show that both the quality characteristics vary significantly between different size-grades, but while the variation in the number of deteriorated pieces between days is not significant, the variation in the number of discoloured pieces between days is significant.

Towing resistance of ottar [i.e. otter] trawls used for shrimps from small mechanised boats

Attempts have been made to determine the towing resistance of the shrimp otter trawls operated from small trawlers off Cochin and the actual resistance on the warps for eight different boats working under the normal fishing conditions have been measured. Engine Horse Power utilised for towing the gear at normal speed and fishing conditions has also been estimated.

A note on the production trend of marine shrimps in India

The paper reviews the production statistics of marine shrimps in the different maritime states of India from 1950 to 1962. It is pointed out that for a correct appraisal of the status of any fishery, it is necessary to have data on effort E and catch per unit effort in addition to the conventional data on catch C. A relationship between U and E has been developed and the status of the fishery of Metapenaeus dobsoni has been discussed in this connection with reference to the data on catch and effort obtained from trawler operations off Cochin.

Occurrence and abundance of Acetes shrimps in the Kutubdia channel of Bangladesh coastal water

This investigation was carried out from June ‘89 to May ‘90 and focuses on the occurrence and abundance of Acetes shrimps in the Kutubdia channel. The shrimps of the genus Acetes occurred throughout the year in the area of investigation. Acetes showed a bimodal peak in occurrence, one in late monsoon season (August - September) and other in pre-monsoon season (February - March). But the maximum number of Acetes shrimps was recorded in March (462 individuals/haul). The Acetes population of this channel was dominated by four species, Acetes erythraeus (38.50%), A. indicus (32.98%), A. chinensis (4.48%) and A. japonicus (3.32%).