aquaculture

Dear readers
There has been some interest from people with previously unpublished research that they would like to offer to the aquaculture community.

If you have undertaken some research and would be interested to see it published so that it is accessible easily to the international aquaculture community please contact me directly and we can discuss how that might happen.

Regards
Lynsey

Research on estimates of genetic parameters for growth traits of the sea urchin, Strongylocentrotus intermedius is available for free download.

There is no published information about heritabilities or genetic correlations for any trait in the sea urchin. This study investigates heritability and genetic correlations for growth traits in sea urchin at 8, 10, and 12 months after metamorphism, a continuation of studies on heritability of growth at juvenile stages of sea urchins Strongylocentrotus intermedius.

The authors, Xiao-lin Liua, Ya-qing Chang, Jian-hai Xiang, and Xue-bin Cao, introduce the report with:

Genetic improvement of breeding stocks becomes more and more important in aquaculture. Even slight improvement in body weight and size would be a major advance since body size at a certain age is a common performance trait in breeding programs. Heritability and genetic correlation are two important parameters, which measure the relative magnitude of additive genetic variation for a trait and covariation between traits. Henderson’s (1973) pioneering work provided a technique that enabled separation of genetic and environmental effects when predicting cattle breeding values. The technique now dominates analysis of data from livestock improvement schemes, both in prediction of breeding values and estimation of genetic parameters.

An economic evaluation of Pacu – Piaractus mesopotamicus juvenile production in different rearing systems is available for free download.

In this study, the authors, Rosangela Kiyoko Jomori, Dalton José Carneiro, Maria Inez Espagnoli Geraldo Martins and Maria Célia Portella, evaluated the costs and gross income related to the production of juvenile pacu, Piaractus mesopotamicus.

The larviculture technique for the production of juveniles usually employed in Brazil is the semi-intensive system, which consists in stocking the larvae in fertilized ponds from the time when exogenous feeding begins until the juvenile stage (Senhorini et al., 1991). Nevertheless, the survival rates obtained with this system are usually low, making large-scale production more difficult.

When rearing common carp (Cyprinus carpio), tambaqui (Colossoma macropomum), and pacu (Piaractus mesopotamicus) larvae in fertilized ponds, Chabalin et al. (1989) obtained survival rates around 35%, 30%, and 20%, respectively, at the end of juvenile rearing. The authors suggested that the pacu juvenile rearing technique needed to be improved.

The Aquaculture Asia Magazine Vol IX No. 3, July-September 2005 is available for free download.

In this issue:
Sustainable aquaculture
Peter Edwards writes on rural aquaculture: Asian Development Bank study on aquaculture and poverty

New ACIAR projects to commence in Indonesia
David McKinnon and Jes Sammut

Assessing the consequences of converting to organic shrimp farming
Xie, Biao, Li, Jiahua and Wang, Xiaorong

Recycling water and making money
Hassanai Kongkeo and Simon Wilkinson

Asia-Pacific Marine Finfish Aquaculture Network
Advances in the seed production of Cobia Rachycentron canadum in Vietnam
Le Xan

Australian success with barramundi cod
Dr Shannon McBride

Brief overview of recent grouper breeding developments in Thailand
Sih-Yang Sim, Hassanai Kongkeo and Mike Rimmer

Application of probiotics in rotifer production systems for marine fish hatcheries
Tawfi q Abu-Rezq and Charles M. James

Research & farming techniques
Contract hatchery systems: A practical approach to procure quality seeds for aquaclubs of small-scale shrimp farmers in India
Arun Padiyar

Recirculation systems: Sustainable alternatives for backyard shrimp hatcheries in Asia?
Thach Thanh, Truong Trong Nghia, Mathieu Wille and Patrick Sorgeloos

Rainbow trout culture in Iran: Development and concerns
Hussein Abdulhai & Mohammad Kazem Seiedi Ghomi

Large-scale growout of spotted Babylon, Babylonia areolata in earthen ponds: Pilot monoculture operation
S. Kritsanapuntu, N. Chaitanawisuti, W. Santhaweesuk and Y. Natsukari

Cage cum pond fish production using mixed sex nile tilapia in Nepal
A.K. Rai, M.K. Shrestha and S. Rai

According to a report on shrimp culture in Hellas (Greece) by Kapiris Kostas of the National Centre for Marine Research in Athens, Greece; originally, two shrimp species were known to exist in the Mediterranean Sea. Five more species from the same family (Penaeidae) were found in the Hellenic sea waters having “emigrated” from the Indian Ocean through the Suez Canal (Lessepsian migration). These species are: Penaeus japonicus, P. semisulcatus, Metapenaeus monoceros, M. stebbingi, and Trachypenaeus tapenaeus. It has been reported that there are some natural population of P. japonicus in the Adriatic Sea and in the region of Cadiz (Spain).

Shrimp is one of the most important catches in the entire world because of the flesh and commercial value. It is characteristic that shrimps were 19.7% of the total imports of the EEC (1993) and their selling prices in Hellas in 1995 increased about 42% (ABH Report, 1994). Kostas determines that it is clearly urgent to culture shrimp in Greece.

Hellenic climatic conditions are most favourable for this type of culture if a species which combines rapid growth rates with a great tolerance to physicochemical conditions is selected. Details about the reproduction and problems of the species culture must be resolved.

Although many problems have already been solved, efforts in Greece were not always successful. The reasons contributing to this lack of success are:
○ The lack of the Hellenic know-how of shrimp culture.
○ Expert foreign scientists were unavailable to help Greek scientists in aquaculture.
○ The non-existence of a state hatchery (broodstock section, larval rearing section).
○ The Ministry of Agriculture and banking establishments has never encouraged this type of culture.
○ The national research centers have never taken the initiative to act in shrimp rearing.
○ The Hellenic investors have low economic abilities and always are looking for ‘money for jam’.

There available grounds in Hellas for shrimp culture. Because of the exploitation of the coastal zones from tourism and agricultural sector there is a limited number of these places, but it is possible for the establishment of 4-5 units in some inshore areas in Thrace, Dodecanese, Peloponnese.