Effects of the embryonic thermal environment on haddock (Melanogrammus aeglefinus) developmental trajectories through exogenous feeding stages
Martell, D.J.; Kieffer, J.D.; Trippel, E.A. (2006). Effects of the embryonic thermal environment on haddock (Melanogrammus aeglefinus) developmental trajectories through exogenous feeding stages. Mar. Biol. (Berl.) 149: 177-187. http://dx.doi.org/10.1007/s00227-005-0190-3
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
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| Authors | | Top |
- Martell, D.J.
- Kieffer, J.D.
- Trippel, E.A.
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| Abstract |
Detailed development of haddock (Melanogrammus aeglefinus) embryos and larvae was studied in several embryonic thermal rearing environments. Using defined reference points (landmarks), development of various tissues including muscle was mapped throughout early ontogeny. The onset of most landmarks was unaffected by temperature as a proportion of time to the initiation of exogenous feeding (standardized developmental time). However, blastopore closure, notochord vacuolation, retinal pigmentation, the appearance of blood cells, and hatching occurred later in development at lower temperatures. Appearance of the optic lumen, neural tube cavitation, and increased myofibril density per deep cell occurred earlier at lower temperatures. Changes in relative order and temporal sequence of developmental events were observed among temperature groups. Notochord (from 30 to 7% of developmental time) and eye development (from 45 to 33% developmental time) was accelerated with increased embryonic temperature, while myofibrillargenesis (from 60 to 88% developmental time) and neural tube development was similarly slowed (71–85% developmental time). The rate of gut development continued to be greater in larvae from higher incubation temperature groups beyond hatch in spite of the absence of temperature variation. Incubation temperature was found to have had a differential but significant effect on the development of various tissues and structures that affected the form and, possibly, function of exogenous feeding haddock. |
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