Premium
Temperature Effects on Feed Utilization and Growth of Postsettlement Stage Nassau Grouper
Author(s) -
Ellis Simon C.,
Watanabe Wade O.,
Ellis Eileen P.
Publication year - 1997
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1997)126<0309:teofua>2.3.co;2
Subject(s) - grouper , zoology , biology , juvenile , epinephelus , fishery , growth rate , relative growth rate , feed conversion ratio , body weight , ecology , fish <actinopterygii> , mathematics , geometry , endocrinology
Feed utilization and growth of hatchery‐reared, postsettlement stage Nassau grouper Epinephelus striatus (mean weight = 3.20 g) were compared for 63 d at temperatures of 22, 25, 28, and 31°C under controlled laboratory conditions. Final weights ( W f ) and specific (SGR) and relative (RGR) growth rates were significantly ( P < 0.05) higher at 28 and 31°C ( W f = 10.5–12.4 g, SGR = 1.95–2.07%/d, RGR = 246–273%) than at 22 or 25°C ( W f = 7.33–8.70 g, SGR = 1.32–1.52%/d, RGR = 131–164%). Temperature unit requirements per gram of growth (range = 342–234°C × d/g) also appeared to decrease with temperature within this range. Higher growth with increasing temperature was related to feed consumption (% body weight/d), which increased significantly ( P < 0.05) from 1.60 at 22°C to 2.23 at 31°C. Feed conversion ratio (weight fed/weight gained: range = 1.23–1.04) and condition factor (10 3 × weight/length 3 ; range = 30.6–31.7) did not differ among treatments. Survival did not differ and remained high (range = 96.4–100%) under all treatments. The results demonstrate that sea temperature within an ecological range has pronounced and direct effects on feeding and growth of juvenile Nassau grouper. Based on in situ sea temperature data in a known juvenile habitat, we hypothesize that timing of spawning in relation to seasonally changing sea temperatures in these habitats may be important in determining juvenile growth rates, vulnerability to predation, and hence, year‐class strength. A temperature range of 28–31°C is recommended for culture of early juveniles, although higher temperatures may be feasible.