Jason S. Broach

Broodstock Selection Criteria for Induced Spawning of Channel Catfish for the Production of Channel × Blue Catfish Hybrid Fry and the Influence of Temperature

Abstract Hybrid catfish (female channel catfish Ictalurus punctatus × male blue catfish I. furcatus) can be obtained by induced spawning and artificial fertilization; the results, however, are variable. A threshold degree of maturity must be reached before broodfish can be induced to spawn, but selection of such fish can be very subjective. In the present study, female brood channel catfish were classified subjectively as poor, fair, or good as well as on the basis of body weight, total body length, body width and girth, and the ratios of these measurements. Brood females were held at 24, 26, and 28°C in 100-L aquaria and injected with synthetic analogues of luteinizing hormone releasing hormone at 20 μg/kg, followed 12 h later by an additional injection of 100 μg/kg. Data were collected regarding spawning success, time to egg release following injection, fecundity, egg diameter, hatching, and survival rates. For the population as a whole at all three temperatures the spawning rate was 73.8%, but among fe...

Captive Volitional Spawning and Larval Rearing of Pigfish

Abstract Pigfish Orthopristis chrysoptera have been identified as a species with potential for commercial production; however, lack of established culture protocols remain a major obstacle. To date, there is no scientific literature that adequately examines captive spawning and culture of this species. The purpose of this study was to evaluate volitional spawning and larval culture of Pigfish. Additionally, a preliminary larval feeding regime was investigated and growth and development of Pigfish larvae were documented. A fecundity of 1,147,149 eggs per female (2,959 eggs/g body weight) was calculated based on 58 recorded volitional spawning events. Larval survival ranged from 6.5% to 100% through 25-d posthatch (DPH). Larvae were observed to initiate swim bladder inflation by 9 DPH, and 100% percent of larvae exhibited notochord flexion by 19 DPH. An effective feeding regime was established that incorporated the nauplii of the copepod Pseudodiaptomus pelagicus, the rotifer Brachionus plicatilis, and Arte...

Effects of Increasing Docosahexaenoic Acid (DHA) and Arachidonic Acid (ARA) in Brood Diets of Monodactylus sebae on Fecundity, Egg and Larval Quality, and Egg Fatty Acid Composition

Abstract The Guinean Fingerfish Monodactylus sebae is a popular euryhaline ornamental fish species with limited aquaculture production. One of the bottlenecks to commercial production is lack of knowledge of the nutritional requirements for broodstock. Therefore, three broodfish diets were formulated and fed to Guinean Fingerfish broodstock to determine their quantitative and qualitative effects on egg production and egg and larval morphology. The dietary treatments consisted of a control, a diet with increased docosahexaenoic acid (DHA), and a diet with increased DHA and arachidonic acid (DHA + ARA). Broodfish fed the DHA + ARA diet spawned more frequently than broodfish fed the DHA diet and those fed the control diet. The greatest egg production was also observed from broodfish fed the DHA + ARA diet. The mean hatching success of floating eggs was not significantly different among diets. The mean egg and oil globule diameters for both floating and sinking eggs were significantly smaller for broodfish fe...

Protracted volitional spawning of pinfish Lagodon rhomboides and changes in egg quality and fatty-acid composition throughout the spawning season

Spawning performance of pinfish Lagodon rhomboides without use of hormonal aids was monitored over an extended season. Nearly three million eggs were obtained from 75 spawns collected over a 90-day consecutive period from a single population of four brood fish (1M:1F). A mean ± s.d. batch fecundity of 30·27 ± 22·64 eggs g-1 female was estimated with 98·0 ± 0·06% of the batch composed of floating eggs which were 1·04 ± 0·04 mm in diameter and 85·71 ± 27·59% fertile. Floating eggs successfully hatched 54·65 ± 29·13% of the time which yielded larvae that were 2·59 ± 0·24 mm in length. Fatty acids within floating eggs were largely represented by polyunsaturated fatty acids (45·30 ± 2·14% of total fatty acids) of which linoleic acid [(c18:2n-6cis) 3·49 ± 1·69% trifluoroacetic acid (TFA)] and docosahexaenoic acid (DHA) [(c22:6n-3) 28·47 ± 1·48% TFA] represented the majority of fatty acids for n-6 and n-3 polyunsaturated fatty acids, respectively. The strongest correlations between fatty acids and hatching success and larval survival to first feeding were observed for the DHA:EPA (eicosapentaenoic acid; c20:5n-3) ratio and total n-6 polyunsaturated fatty-acids levels, respectively. These data demonstrate potential for producers to rely on natural spawns for extensive egg production and provide a baseline for future development of natural spawning protocols of captive L. rhomboides.

Effects of Brood Density and Spawning Substrate Type and Orientation on the Reproductive Output of Seminole Killifish in Tanks

AbstractAquaculture of baitfish has the potential to produce and supply desired species and sizes to meet year-round market demand. The Seminole Killifish Fundulus seminolis is native to Florida and has recently emerged as a candidate for marine baitfish aquaculture because of its ability to survive acclimation to seawater, fast growth, and resilient larvae. Experiments were conducted to identify which spawning substrate materials and orientations were preferred by Seminole Killifish and to evaluate effects of broodfish stocking density on reproductive output. Results indicated that Seminole Killifish required a suitable substrate to be present for successful spawning and egg deposition. Broodstock spawned nearly all eggs onto fiber spawning mats when offered both mat and sand substrates. There was no significant difference in the number of eggs recorded among spawning mats regardless of orientation. Seminole Killifish held in outdoor tanks at a 2:1 (female : male) sex ratio had similar total egg producti...

Induced Spawning and Larval Culture of Golden Trevally

AbstractThe Golden Trevally Gnathanodon speciosus is a popular sport, food, and ornamental fish native to the tropical Indo-Pacific region, yet there is little information regarding aquaculture technologies. A group of Golden Trevally broodfish was acquired from a local public aquarium in an effort to attempt captive spawning and larval culture. Broodfish were held in 4,500-L recirculating aquaculture systems and conditioned on a mixed diet of squid, capelin, and krill. Once water temperatures were averaging 26°C, Ovaplant was administered to mature broodfish (six males, two females) in one of the systems. Broodfish spawned on three separate occasions after this hormone administration, releasing probably 35,000 eggs/female during each spawn. Fertile eggs from two of these spawns were used for larval culture attempts. Larvae were stocked into five 104-L tanks at densities up to 173 larvae/L. Throughout larval culture trials, larvae were fed a combination of copepod nauplii, enriched rotifers, Artemia naupl...