Title

Bioenergetics and growth of dolphin, Coryphaena hippurus

Date of Award

1992

Availability

Article

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Marine Biology and Fisheries

First Committee Member

Peter L. Lutz, Committee Chair

Second Committee Member

Edwin S. Iversen, Committee Member

Abstract

Metabolism, growth and energy utilization of dolphin were studied at 26$\sp\circ$C during all life stages. Experimental organisms included wild and cultured adult fish (0.9-4.2 kg) and eggs, larvae and juvenile (1.5-43 g) from $F\sb1$, and $F\sb7$ generations inbred in captivity. The mean rates of oxygen consumption (VO$\sb2$ = $\mu$l O$\sb2$ indiv.$\sp{-1}$ h$\sp{-1}$) by eggs and 1-18 day-old larvae were 0.25 and 4.18, respectively. The weight-specific oxygen consumption (QO$\sb2$ = $\mu$l O$\sb2$ mg dry wt$\sp{-1}$ h$\sp{-1}$) by eggs and larvae were 1.8 and 11.34, respectively. Both VO$\sb2$ and QO$\sb2$ increased significantly with development. Respiratory quotients (CO$\sb2$/O$\sb2$) by eggs and 1-18 day-old larvae had a mean value of 0.57 and were independent of age. Specific growth rate of larvae ranged from 16-34% bw d$\sp{-1}$. Endogenous rate of nitrogen excretion was 2.11 $\times$ 10$\sp{-3}$ $\mu$mol ammonia-N mg dry wt$\sp{-1}$ h$\sp{-1}$. Ingestion rates by larvae corresponded to 166% of their body calories daily (over 80% of their body weight).The standard metabolic rate of adult dolphin (0.21 mg O$\sb2$ g$\sp{-1}$ h$\sp{-1}$) and the routine, swimming and feeding metabolism of juveniles (0.71, 0.97 and 1.5 mg O$\sb2$ g$\sp{-1}$ h$\sp{-1}$, respectively) were studied. Their hematological parameters were also determined: hematocrit (39.85%), hemoglobin (11.53 g dl$\sp{-1}$) and erythrocyte (3.1326 $\times$ 10$\sp6$ mm$\sp3$). The mean heart rate was 136 beats min$\sp{-1}$. Specific growth rates of 1-9.5 month-old fish decreased from 10 to 4.3% bw d$\sp{-1}$ within the experimental period. The rate of food ingestion by juveniles was about 4% bw d$\sp{-1}$, and their mean rate of nonfecal endogenous nitrogen excretion was 0.0052 mg/0.29 $\mu$mol ammonia-N g$\sp{-1}$ h$\sp{-1}$. Energy budgets for larvae and juvenile stages of Coryphaena hippurus were calculated as: (a) for larvae: 100 $\pm$ 21(I) = 40 $\pm$ 18(M) + 45 $\pm$ 5(G) + (1.2 $\pm$ 0.4(U) + 13.8 (F)) (E), or, in cal d$\sp{-1}$: 4.7 $\pm$ 1(I) = 1.9 $\pm$ 0.9(M) + 2.1 $\pm$ 0.2(G) + (0.05 $\pm$ 0.01(U) + 0.65(F)) (E) (b) for juveniles: 100 $\pm$ 4(I) = 47 $\pm$ 12(M) + 35 $\pm$ 11(G) + (0.02 $\pm$ 0.008(U) + 17.98(F)) (E), or, in cal d$\sp{-1}$: 3,410 $\pm$ 14(I) = 1,605 $\pm$ 445(M) + 1,210 $\pm$ 378(G) + (36.53 $\pm$ 14.6(U) + 558.5(F)) (E); where I = ingestion; M = metabolism; G = growth; U = nonfecal excretion; F = fecal excretion; and E = total excretion.The budgets suggest that dolphin larvae and juveniles have a higher energetic efficiency than other teleosts by using a proportionally larger portion of the total gross energy ingested for growth and metabolism than for excretion. Their feed conversion, assimilation and growth efficiencies were comparatively higher than for other fishes.

Keywords

Biology, Oceanography; Biology, Animal Physiology; Agriculture, Animal Culture and Nutrition

Link to Full Text

http://access.library.miami.edu/login?url=http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9314508