Date of Award

8-2013

Level of Access

Campus-Only Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Marine Biology

Advisor

David W. Townsend

Second Committee Member

David M. Fields

Third Committee Member

Linda Kling

Abstract

The marine ornamental fish aquaculture industry relies on unsustainable, wild- collected fishes to meet market demand. The goal of this research was to investigate key bottleneck issues in marine ornamental fish aquaculture. This was achieved in several steps. First, a broodstock holding system was designed and constructed to hold mature pairs of the pelagic spawning flame angelfish (Centropyge loriculd). Then, ten pairs of C. loricula were acquired and conditioned for spawning. Fertilized viable eggs were harvested by way of custom-built egg collectors.

Experiments were conducted to investigate depletion of endogenous yolk reserves of C. loricula larvae in relation to development, survival and onset of feeding. Larvae of C. loricula are immature at hatch, and utilize the majority of endogenous resources within 40 hours post fertilization (hpf). Exhaustion of yolk sac and oil globule was complete at 91 and 139 hpf, respectively. Onset of first-feeding occurred at 87 hpf and the duration of the “critical period,” when larvae transition from endogenous yolk reserves to exogenous feeding lasted 100 hours.

Feeding and stocking density experiments were conducted on a small copepod species Parvocalanus crassirostris, a potential first-feeding live prey, to improve culture methods of this zooplankton. Total copepod egg production increased with increasing stocking densities of copepods and daily copepod egg production of up to 100,000 eggs per liter per day was observed when the copepods were fed the microalgae Isochrysis galbana.

Specialized recirculation aquaculture systems (RAS) were built and tested for the incubation and first-feeding of fragile C. loricula larvae. Survival was highest in the RAS that incorporated kreisel tanks which was then chosen for further feeding experiments using P. crassirostris nauplii as prey. Fish larvae fed copepod nauplii survived longer than unfed larvae and their vascular system and musculature were more developed.

A final study was conducted to investigate shipping of fish in polyethylene shipping bags. Gut evacuation rates for starvation and tolerance to ammonia and pH change were investigated for Clownfish (Amphiprion sp.) and dottyback (Pseudochromis sp). A series of simulated shipping experiments provided baseline data for water chemistry changes based on fish biomass, water volume and shipping time.

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