Improvement of larval rearing technique for mass seed production of snow crab Chionoecetes opilio

Abstract

Larval rearing experiments were conducted to examine the potential for mass seed production of the snow crab Chionoecetes opilio using a total of eight 20-kL tanks. Tanks were equipped with agitators, which move the water using a rectangular blade to prevent the zoeas sinking to the bottom of the tank. Larval rearing water was treated with sodium nifurstyrenate once a week to reduce the chance of larval infection by pathogenic bacteria. Zoeas were fed with rotifers and Artemia nauplii. A total of 122 830 megalops and 16 660 first-stage crabs were produced. Thus, the potential for mass seed production of snow crab was determined. Survival rates up to the megalopal stage were high in tanks with a feeding regime that fed rotifers to larvae through an entire zoeal stage. This study also describes the fatty acid composition of snow crab larvae. It revealed that the first zoeas had a high DHA content and DHA/EPA ratio, but these values significantly decreased in the second stage zoeas and megalops. Improving the DHA content and/or DHA/EPA ratio of larvae should be important in studies on mass seed production technology of the snow crab.

Starvation of Artemia in larval rearing water affects post-larval survival and morphology of the swimming crab, Portunus trituberculatus (Brachyura, Portunidae)

“…And therefore, nutritional enrichment of Artemia using various materials is commonly practiced in commercial hatcheries (Lee and Ostrowski, 2001;Marte, 2003;Shields, 2001). On the other hand, sufficient attention has not been paid on maintenance of nutritional status of Artemia after being supplied into larval rearing water, and supplementing with Artemia in combination with Nannochloropsis and Chlorella, which are indigestible for Artemia nauplii, has been adopted during seed production of various species including crustacean and finfish species (Kogane et al, 2007;Lee and Ostrowski, 2001;Marte, 2003;Shields, 2001). Starving Artemia can occur and exert a negative effect on cultured animals in these cases.…”

Economic Feasibility of Aquaculture of the Giant BarnacleAustromegabalanus psittacusin Southern Chile

“…The giant barnacle has many culture advantages over other crustaceans, such as lobster, snow crab, or prawn, which are carnivorous, mobile, and require exogenous food in cultures (Epelbaum & Kovatcheva 2005Kogane et al 2007, Schmalenbach et al 2009). The giant barnacle, on the other hand, is a sessile, omnivorous filterer in its adult phase, experiencing rapid growth (Lo´pez et al 2010).…”

Importí­¢ncia do rotí­­fero como alimento no desenvolvimento larval do caranguejo-uçá

“…A ausência de ácidos graxos poli-insaturados de cadeia longa em rotíferos e em A. franciscana corrobora os resultados de MANN et al (2001), sendo devida ao fato de não ter ocorrido o enriquecimento antes de serem fornecidos às larvas e, também, de as microalgas utilizadas no protocolo alimentar, ricas nestes compostos (LAVENS e SORGELLOS, 1996), terem sido, provavelmente, ingeridas pelo alimento vivo. Outras fontes de ácidos graxos de cadeia longa provêm da reserva vitelínica e da capacidade de as larvas de caranguejos converterem ácidos graxos poli-insaturados de cadeia curta naqueles de cadeia longa (KOGANE et al, 2007;NGHIA et al, 2007;BELL e TOCHER, 2009).…”

“…Entretanto, a provisão de vários itens como alimento vivo com diferentes características físicas e nutricionais pode trazer dificuldades no cultivo e programação de laboratórios (AL AIDAROOS, 2013). Desta forma, a diminuição ou eliminação do fornecimento dos rotíferos pode reduzir a necessidade de mão de obra, equipamentos, espaço físico, riscos e custos na produção de formas jovens de caranguejos (SUPRAYUDI et al, 2002;RUSCOE et al 2004;BAYLON et al, 2004;KOGANE et al, 2007;BAYLON, 2009;FALEIRO e NARCISO, 2009). O objetivo deste trabalho foi verificar o efeito da exclusão de rotíferos do protocolo alimentar em cada estágio larval e de sua substituição por ração, durante a larvicultura do caranguejo-uçá, sobre a sobrevivência, tempo de desenvolvimento e tamanho das larvas.…”