Matthew A. DiMaggio

Evaluation of a Point-of-Care Blood Analyzer for Use in Determination of Select Hematological Indices in the Seminole Killifish

Abstract Conventional methodologies for hematological analysis are gradually being replaced with new technologies. Point-of-care blood analyzers are both efficient and user friendly. As the use of such technologies becomes more pervasive in current literature, investigations into the accuracy and reliability of point-of-care analyzers for evaluating fish hematological indices are warranted. The purpose of this study was to evaluate a point-of-care blood analyzer (i-STAT®) and chosen cartridge (E3+) against conventionally accepted instrumentation (CAI) for use in determination of hematocrit, sodium, potassium, and chloride values in Seminole killifish Fundulus seminolis. Whole blood, a whole-blood heparin dilution, and undiluted plasma were analyzed in the point-of-care unit to determine hematological parameters of interest. The Bland–Altman method for assessing agreement between two methods of clinical measurement was used as well as calculations of correlation coefficients and two-tailed paired Students...

Culture of Pinfish at Different Stocking Densities and Salinities in Recirculating Aquaculture Systems

Abstract There is great demand for marine baitfish in U.S. coastal states. The supply of marine baitfish in the United States is almost completely wild caught, and this fishery is seasonal and inconsistent. Aquaculture may be able to consistently supply marine baitfish for anglers. Two experiments were conducted to evaluate the effects of stocking density and salinity on the growth and survival of pinfish Lagodon rhomboides cultured in recirculating aquaculture systems. For the stocking density experiment, juvenile pinfish were stocked (50, 200, 400, and 600 fish/m3) into 1,600-L circular tanks in three identical recirculating systems with a salinity of 27 g/L and were cultured for 82 d. Mean survival was not statistically different among densities and ranged from 94.3% to 99.18%. Daily growth of pinfish ranged from 0.35 to 0.39 g·fish−1·d−1. Mean percent weight gain ranged from 624% to 690% and followed a density-dependent trend. Final total length followed a density-dependent pattern, with each increasi...

Osmoregulatory Evaluation of the Seminole Killifish after Gradual Seawater Acclimation

Abstract Aquaculture of marine baitfish species is still in its relative infancy and the increasing value of coastal property is forcing marine aquaculture inland. The Seminole killifish Fundulus seminolis, a freshwater species that is endemic to Florida, has recently emerged as a candidate for marine baitfish aquaculture. Gradual acclimation of Seminole killifish from 0-g/L salinity to natural seawater at 32-g/L salinity was carried out over 24, 48, 72, and 96 h. Physiological analyses of seawater-acclimated fish yielded elevated plasma ion (sodium, potassium, chloride) and osmolality concentrations accompanied by decreases in body weight and muscle water content. Although all of the seawater-acclimated physiological endpoints measured remained significantly different from control values, a general trend signaling the initiation of osmoregulatory compensation was noticed in 96-h values as select analytes began to migrate towards reference values derived from controls. Results of this investigation will c...

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...

Induced Volitional Spawning and Larval Rearing of Pinfish

Abstract Aquaculture of marine baitfish is still in its infancy. Induced spawning of marine baitfish species has the potential to supplement this seasonal capture fishery and offer a consistent supply to anglers. The pinfish Lagodon rhomboides has been identified as a species with potential for commercial production, yet few studies have focused on the induced spawning and larval rearing of this baitfish. The purpose of this study was to evaluate the efficacy of using Ovaprim, composed of a salmon gonadotropin-releasing hormone analog (sGnRHa) and a dopamine antagonist (domperidone), to induce volitional spawning in pinfish. Additionally, a preliminary larval feeding regime was investigated, and growth and development of pinfish larvae were documented. A single dose of 0.50 mL of Ovaprim per kilogram of fish (sGnRHa: 20 μg/mL; domperidone: 10 mg/mL) was sufficient to induce volitional spawning 36–48 h after intraperitoneal injection of female pinfish. Observed fecundity was 2,565 eggs/female (13.1 eggs/g)...

Spawning, Larviculture, and Salinity Tolerance of Alewives and Blueback Herring in Captivity

AbstractPrecipitous declines in wild populations of river herring species (Alewives Alosa pseudoharengus and Blueback Herring A. aestivalis) have led to increased interest in stock enhancement efforts. Additionally, their popularity as a baitfish among recreational anglers has generated interest in commercial production of these species for marine baitfish markets. The objective of this investigation was to elucidate practical culture protocols for captive propagation of these species for commercial and restoration purposes. Wild Blueback Herring, captured during their annual spawning migration, spawned in tanks volitionally, while Alewives required exogenous hormone administration. Larvae of both species were successfully raised through metamorphosis using a feeding regime comprised of enriched rotifers followed by Artemia nauplii and a commercially available diet. Survival of early larvae acclimated to salinities ranging from 5‰ to 15‰ was high for both species (>94.0%) while that for older larvae accli...

Brain aromatase (cyp19a1b) and gonadotropin releasing hormone (gnrh2 and gnrh3) expression during reproductive development and sex change in black sea bass (Centropristis striata)

Teleost fish exhibit diverse reproductive strategies, and some species are capable of changing sex. The influence of many endocrine factors, such as gonadal steroids and neuropeptides, has been studied in relation to sex change, but comparatively less research has focused on gene expression changes within the brain in temperate grouper species with non-haremic social structures. The purpose of the present study was to investigate gonadotropin releasing hormone (GnRH) and brain aromatase (cyp19a1b) gene expression patterns during reproductive development and sex change in protogynous (female to male) black sea bass (Centropristis striata). Partial cDNA fragments for cyp19a1b and eef1a (a reference gene) were identified, and included with known gnrh2 and gnrh3 sequences in real time quantitative PCR. Elevated cyp19a1b expression was evident in the olfactory bulbs, telencephalon, optic tectum, and hypothalamus/midbrain region during vitellogenic growth, which may indicate changes in the brain related to neurogenesis or sexual behavior. In contrast, gnrh2 and gnrh3 expression levels were largely similar among gonadal states, and all three genes exhibited stable expression during sex change. Although sex change in black sea bass is not associated with dramatic changes in GnRH or cyp19a1b gene expression among brain regions, these genes may mediate processes at other levels, such as within individual hypothalamic nuclei, or through changes in neuron size, that warrant further research.

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...

Preferences for and perception of cultured marine baitfish by recreational saltwater anglers in Florida

ABSTRACT There is strong interest in culturing live marine baitfish for anglers. However, there is scant information about saltwater anglers’ perception of cultured baitfish. Thus, a survey was developed and administered to assess recreational saltwater angler’s preferences for baitfish, their attitudes towards cultured baitfish, supply and demand, and specific information about pinfish (Lagodon rhomboides) and pigfish (Orthopristis chrysoptera). An online survey invitation was e-mailed to 227,829 licensed marine recreational anglers in Florida. A total of 14,871 respondents completed some portion of the survey (6.5% response rate). Inshore destinations were the most common fishing trips taken. Live bait was caught by 57.8% of respondents, purchased by 32.1%, and 10.1% did not use live bait. Perceptions of aquaculture as a means of producing bait were 43.8% positive, 20.6% somewhat positive, and 31% unknown. Consistent availability and price were identified by anglers as the two most important characteristics for an aquaculture produced marine baitfish.

Peritoneal Pigmentation in Purebred and Hybrid River Herring

AbstractRiver herring (Alewives Alosa pseudoharengus and Blueback Herring A. aestivalis [bluebacks]) are congeneric, anadromous clupeid fishes that hybridize in areas of sympatry. Peritoneal pigmentation is the most diagnostic characteristic used to distinguish the species, but pigmentation has not been examined in hybrids. We developed a molecular-based assay to distinguish purebred river herring species from F1 hybrids and compared the peritoneal pigmentation among captive-raised purebred and hybrid individuals. Both wild-caught Alewife and blueback females tank-spawned with conspecific and congeneric males, but Alewives required exogenous hormone administration. Larvae of both species and hybrids were raised for ∼290 d posthatch, and peritoneal pigmentation was quantified. A nuclear gene (rag2) restriction fragment length polymorphism assay was used for species and hybrid identification. The peritoneal pigmentation was significantly darker in hatchery-spawned bluebacks than in Alewives, and hybrids exh...