Influence of food density and temperature on ingestion, growth and settlement of Pacific oyster larvae, Crassostrea gigas

Abstract

Ingestion, growth and metamorphosis of Pacific oyster, Crassostrea gigas, larvae were studied under controlled conditions of food density and temperature using a combination of a flow-through rearing system and a hydrobiological monitoring device. In a first experiment larvae were exposed to three different phytoplankton densities (12, 20 and 40 cells µl-1) while in a second trial larvae were reared at five different temperatures (17, 22, 25, 27 and 32°C). Both food concentration and temperature significantly affected the larval physiology throughout the entire development from D-veliger to young spat. Larvae survived over a wide range of both environmental parameters with high survival at the end of experiments. The feeding functional response provided the maximal ingestion rate (50 000 cells larva-1 day-1) which occurred at an algal density of 20 cells µl-1 surrounding the larvae and 25 °C. At the highest temperature (32 °C), maximal growth and metamorphosis performances were reached in less than 2 weeks while the lowest temperature (17°C) consistently inhibited ingestion and growth over the entire larval period. The estimate of the Arrhenius temperature (TA) was 11000 K for C. gigas larvae. Larval development could be divided on the basis of feeding activity into an initial mixotrophic period with a lower and constant ingestion over the first days (from D-stage to early umbonate larva of ≈110 µm length) followed by an exotrophic phase characterized by a sharp increase in ingestion (umbonate to eyed of ≈ 300 µm length) and, finally, a third period for larvae 300 µm during which ingestion decreased suddenly because of metamorphosis. Optimum larval development and settlement of the oyster C. gigas occurred at 27 °C and an increasing food supply as the larvae were growing. A food density of ≥20 cells µl-1 of T-ISO + CP or CG (1:1 cells number) in the culture water was required to maximise growth and metamorphosis success.

Effects of Alexandrium minutum exposure upon physiological and hematological variables of diploid and triploid oysters, Crassostrea gigas

“…Relationships between food quality and quantity, energy storage, and reproduction are now well established in C. gigas (Soudant et al, 1999;Berthelin et al, 2000;Royer et al, 2008;Rico-Villa et al, 2009). These observations suggest that HAB exposure, by affecting nutrition-related functions, may impact reproduction processes and gamete output.…”

Feeding selectivity of bivalve larvae on natural plankton assemblages in the Western English Channel

“…In particular, the larvae appear to select for nanoeukaryotes, especially coccolithophores, with these prey groups contributing >75 % of the carbon ingested. The focus of many previous studies on larval bivalve feeding has been based around commercially important species in laboratory environments (Baldwin and Newell 1995;Rico-Villa et al 2009;Ben Kheder et al 2010). From these studies, it is thought that the diet of bivalve larvae consists mostly of nanoplankton (<20 µm), including dinoflagellates, Isochrysis spp.…”

“…From these studies, it is thought that the diet of bivalve larvae consists mostly of nanoplankton (<20 µm), including dinoflagellates, Isochrysis spp. (Rico-Villa et al 2009) and Synechococcus spp. (Baldwin 1995).…”

“…(Baldwin 1995) and Isochrysis spp. (Rico-Villa et al 2009). In addition, several studies have suggested bacteria and picoplankton as important sources of carbon for bivalve larvae, including detritus particles and smaller Abstract Meroplankton, including bivalve larvae, are an important and yet understudied component of coastal marine food webs.…”

Ingestion size of food microalgae of the Pacific oyster Crassostrea gigas larvae

“…다음으로 구순 (labial palps)의 역할 로 입으로 먹이입자가 들어가기 전 사전 먹이입자의 크기를 선 별하고, 입자의 크기가 크면 위분 (pseudofeces)으로 배출 한 다 (Newell and Jordan, 1983;Shumway et al, 1985;Defossez and Daguzan, 1996). , 1979;Bayne, 1983;Strathmann, 1987;Gallager, 1988;Riisgård, 1988;Aldana-Aranda et al, 1994;Baldwin, 1995;Cognie et al, 2001;Ponis et al, 2003;Martínez-Fernández et al, 2004;Rico-Villa et al, 2009 , 1979;Lucas and Rangel, 1983;Aldana-Aranda et al, 1991, 1994. μm가 적당하고, 편모를 가지고 있는 경우에는 전체크기가 10 μm이하가 되어야 유생의 먹이로써 적당하다 (Walne, 1974;Wisely and Reid, 1978;Riisgård et al 1980;Fritz et al 1984;Sprung 1984;Gallager 1988;Riisgård 1988), 특히 2-4 μm에서 가자 활발한 섭취를 보였 고 (Wilsion 1980; Baldwin 1995), 동화율도 가장 높았다 (Riisgård et al 1980;Sprung 1984;Riisgård 1988 …”