Yellowtail kingfish
Scientific name: Seriola lalandi
Spawning, Eggs and Larvae
Yellowtail kingfish are a marine fish with a circumglobal distribution, and are an important sport fish and aquaculture species in the southern hemisphere. My PhD thesis investigated the ontogenetic (age-related) development of metabolism in yellowtail kingfish.
At the time my thesis started very little was known about early development in this species. Yellowtail kingfish were being reared in captivity for aquaculture production at the NIWA Bream Bay Aquculture Park, in northern New Zealand. It was here that fellow student Cea Smith and I worked together to describe the captive spawning behaviour and early development of this species. The adult kingfish were kept in large indoor tanks, where water temperature and photoperiod could be controlled to simulate the spawning conditions the fish experience in the wild. Analysis of the spawning behaviour showed that typically one female would spawn with one or two males at a time.
Use this link if the video won't play in your browser.
The spawned eggs were positively buoyant, approximately 1 mm in diameter, and were collected from the water surface and incubated. As is seen in many other marine fish species, the eggs had a single oil droplet inside.
Hatching time was 60-120 hours depending on the incubation temperature.
The oil droplet volume decreased during embryonic and larval development.
Although the oil droplet volume decreased, work by Hilton et al showed that the total body lipid content remains fairly constant during the embryonic and pre-feeding larval phase. Total body protein and glucose/glycogen content was not found to change significantly, so neither lipid, protein nor carbohydrate was the pre-feeding energy source. A rapid decrease in the concentration of free amino acids (i.e. not bound into proteins) was observed along with an increase in ammonia concentration (a waste product of amino acid break down). This suggests that yellowtail kingfish predominatly use free amino acids as an energy source during the pre-feeding phase of development.
--------------------------------------------------------------------------
This research was funded by the NZ Foundation for Research Science and Technology, and I was supported by a NZ Tertiary Education Commission Bright Futures Doctoral Scholarship.
--------------------------------------------------------------------------
This research has been published and is available as follows:
Moran, D.; Smith, C. K.; Gara, B. G.; Poortenaar, C.W. (2007). Reproductive behaviour and egg development in yellowtail kingfish (Seriola lalandi Valenciennes 1833). Aquaculture 262: 95-104.
doi:10.1016/j.aquaculture.2006.10.005 ------- get PDF of paper
Moran, D.; Wells, R. M. G.; Gara, B. G. (2007). Energetics and metabolism of yellowtail kingfish (Seriola lalandi Valenciennes 1833) during embryogenesis. Aquaculture 265: 359-369.
doi:10.1016/j.aquaculture.2007.02.003 ------- get PDF of paper