Craig A. Watson

Dynamic regulation of the transcription initiation landscape at single nucleotide resolution during vertebrate embryogenesis

Spatiotemporal control of gene expression is central to animal development. Core promoters represent a previously unanticipated regulatory level by interacting with cis-regulatory elements and transcription initiation in different physiological and developmental contexts. Here, we provide a first and comprehensive description of the core promoter repertoire and its dynamic use during the development of a vertebrate embryo. By using cap analysis of gene expression (CAGE), we mapped transcription initiation events at single nucleotide resolution across 12 stages of zebrafish development. These CAGE-based transcriptome maps reveal genome-wide rules of core promoter usage, structure, and dynamics, key to understanding the control of gene regulation during vertebrate ontogeny. They revealed the existence of multiple classes of pervasive intra- and intergenic post-transcriptionally processed RNA products and their developmental dynamics. Among these RNAs, we report splice donor site-associated intronic RNA (sRNA) to be specific to genes of the splicing machinery. For the identification of conserved features, we compared the zebrafish data sets to the first CAGE promoter map of Tetraodon and the existing human CAGE data. We show that a number of features, such as promoter type, newly discovered promoter properties such as a specialized purine-rich initiator motif, as well as sRNAs and the genes in which they are detected, are conserved in mammalian and Tetraodon CAGE-defined promoter maps. The zebrafish developmental promoterome represents a powerful resource for studying developmental gene regulation and revealing promoter features shared across vertebrates.

Artificial Reefs, the Attraction-production Issue, and Density Dependence in Marine Ornamental Fishes

Artificial reefs may provide a useful tool to enhance production of marine ornamentals and to divert detrimental harvesting activities from sensitive natural habitat. The efficacy of this strategy depends, in part, on the extent to which artificial reefs contribute to new production (vs. attract fishes from natural habitat) and therefore benefit harvested populations on a local and regional basis. Here the attraction and production hypotheses and their application to marine ornamentals are presented. Specifically, it is discussed how the strength and timing of density dependence can affect the response of fish population dynamics to artificial reefs. In addition to this discussion, examples of density dependence in marine ornamentals and related reef fishes are provided. Based on this information, a simple conceptual model is presented to clarify the role of density dependence, and this is followed by a discussion on the use of artificial reefs in the management and production of marine ornamentals. Finally, unresolved scientific issues that remain to be addressed are provided.

Survey of Ovaprim Use as a Spawning Aid in Ornamental Fishes in the United States as Administered through the University of Florida Tropical Aquaculture Laboratory

Abstract Ovaprim is a commercial product used as a spawning aid in fishes and contains a salmon gonadotropin-releasing hormone analog and a dopamine antagonist. Since 2005, the use of Ovaprim in commercial ornamental fish production has been through enrollment with the University of Florida Tropical Aquaculture Laboratory in an Investigational New Animal Drug (INAD) study. A database is maintained to provide information to the U.S. Food and Drug Administration on product effectiveness and target animal safety. There were 25 fish species in 17 genera and 10 families in the INAD database. Ostariophysan fishes constituted 84% of the species and 99.9% of the individuals. The goldfish Carassius auratus was numerically the dominant species (80% of individuals). Nearly 40,000 fish in total were injected with Ovaprim; ovulation was induced in 92% of females and spermiation was induced in 96% of males, primarily reflecting extensive use in cyprinid fishes. Conversely, average success rates across all species were ...

Effects of Tricaine Methanesulfonate, Hypno, Metomidate, Quinaldine, and Salt on Plasma Cortisol Levels following Acute Stress in Threespot Gourami Trichogaster trichopterus

Abstract Blood plasma cortisol concentration is an indicator of stress in fish, and anesthetics may serve to ameliorate stress and reduce the cortisol response. Previous studies have concentrated on cold- and warmwater species; little information exists for tropical fishes. Mortalities are increased after handling stress of threespot gourami Trichogaster trichopterus (Osphronemidae), a commonly cultured tropical ornamental fish. Plasma cortisol levels were evaluated in threespot gourami after a handling stressor and treatment with one of four anesthetics—tricaine methanesulfonate (TMS; 60 mg/L), metomidate (0.8 mg/L), quinaldine (5 mg/L), and Hypno (0.14 mg/L)—or salt (NaCl; 3 g/L). Fish in all anesthetic treatments had significantly lower cortisol levels than either salt-treated fish or the untreated controls. Therefore, the use of such anesthetics should be beneficial in reducing handling stress. Based on our data, further studies refining the use of anesthetics, particularly metomidate and quinaldine, ...

A Florida Marine Ornamental Pathway Risk Analysis

An expert panel of 18 importer, wholesaler, retailer, producer, harvester, researcher, extension, and agency representatives implemented a known risk analysis process to assess risks associated with the marine ornamental pathway. The participants produced a literature review, marine ornamental trade description, assessed the ecological risks to Florida waters, determined the escape risk at each link and node in the pathway, and suggested risk mitigation actions. Annually, the global marine ornamental trade includes 1,500 fish species, 200 coral species, and 500 invertebrate species (excluding coral), with sale of approximately 20 million fish specimens, 10 million invertebrate specimens (excluding coral), and 10 million coral pieces. Currently, 28 exotic ornamental marine fish species have been observed in Florida waters. Two of the 28 fish species (a species complex) are established as reproducing populations in mid-Atlantic and South Atlantic waters. Participants examined the potential for economic, environmental, or perceived (social or political) effects as a consequence of marine ornamental species becoming established in Florida waters. They were very certain the potential economic costs were low and the economic benefits high based upon literature and general knowledge. Potential and real environmental effects were judged to be low based upon literature and their combined observations. However, the participants were very certain the perceived consequences, social and political, were high based upon concerns identified in the scientific literature and the use of emotive language in public media when nonindigenous species are discussed. Risk mitigation activities were suggested for the unlicensed direct consumer sales link and the consumer node.

Preliminary Observations of Topical Gill Application of Reproductive Hormones for Induced Spawning of a Tropical Ornamental Fish

Abstract Hormone injection is a common spawning induction technique in aquaculture but is of limited use in small species with low fecundity. An alternative to injection for such species is topical gill application. We conducted an experiment with female rainbow sharks Epalzeorhynchos erythrurus (Cyprinidae) in one control group and three treatment groups: (1) topical gill application of dimethyl sulfoxide (DMSO), (2) topical gill application of DMSO and Ovaprim, and (3) an Ovaprim intramuscular (IM) injection. Ovaprim contains a salmonid gonadotropin-releasing hormone analog and a dopamine antagonist. Fish were anesthetized, treated, and placed into recovery tanks. Fish were manually checked for ovulation by exerting abdominal pressure at 8, 10, and 11 h posttreatment and were observed for mortality during a 24-h period. Ovulation varied significantly: we found no ovulation of females in the control or DMSO groups, 78% ovulation in the DMSO plus Ovaprim group, and 100% ovulation in the Ovaprim IM injecti...

Investigational Use of Metomidate Hydrochloride as a Shipping Additive for Two Ornamental Fishes

During shipping, ornamental fish can be stressed due to handling, high stocking densities, and deteriorating water quality. Adding sedatives, such as metomidate hydrochloride, to shipping water may improve fish survival rates and the percentage of fish in saleable condition. Although the effects of metomidate hydrochloride on the stress response in fish have been studied, its application as a shipping additive has not been well investigated, particularly for tropical ornamental fishes shipped under industry conditions. Convict cichlids Cichlasoma nigrofasciatum and black mollies Poecilia sphenops were evaluated for 7 d after a 24-h period of exposure (including ground and air transport) to one of four metomidate hydrochloride concentrations: 0.0, 0.2, 0.5, and 1.0 mg/L. Immediate posttransport and cumulative mortality data, as well as 12-h and 7-d posttransport appearance and behavior scores, were generated. In convict cichlids, the highest dose of metomidate hydrochloride (1.0 mg/L) reduced mortality (0% compared with cumulative means of 5.5-9.2% in other groups) and increased the percentage of saleable fish (91.7% were immediately saleable compared with 12.5-50% in other groups). No effect was detected in black mollies at any concentration tested. Metomidate hydrochloride showed promise as a shipping additive for convict cichlids, but further studies are warranted to evaluate species-specific responses in other ornamental species.

Evaluation of emamectin benzoate for the control of experimentally induced infestations of Argulus sp. in goldfish and koi carp.

The effect of 0.2% emamectin benzoate (SLICE; Intervet/ Schering-Plough Animal Health, Roseland, New Jersey) administered in top-dressed, pelleted commercial fish feed was evaluated for control of freshwater Argulus sp. in goldfish Carassius auratus and koi carp, a variant of common carp Cyprinus carpio, in freshwater aquaria at 24-25 degrees C. Sixteen individually housed goldfish were each exposed to 37 Argulus. The number of fish lice attached to each fish at the start of the experiment was not determined; however, the total number of motile fish lice in each aquarium (on fish and in the water) was determined at the start and end of each experiment. Eight goldfish were fed the control diet (0 microg x kg fish biomass(-1) x d(-1)) and eight were fed the medicated diet (50 microg x kg fish biomass(-1) x d(-1)) for seven consecutive days. After treatment, fish louse infestation in controls was 20.5 +/- 1.5 (mean +/- SE) lice per fish. No Argulus were found on fish in the treated group. In a separate experiment, 10 individually housed koi were each exposed to 128 Argulus. Five koi were fed the control diet and five were fed a low-dose medicated diet (5 microg x kg fish biomass(-1) x d(-1)) for 7 d. After treatment, fish louse infestation among the controls was 14.6 +/- 3.8 lice per koi. No Argulus were found on koi in the treated group. Hence, a 7-d regimen of oral emamectin benzoate controlled experimental infestation of Argulus when administered to goldfish at 50 microg x kg fish biomass(-1) x d(-1) and to koi at 5 microg x kg fish biomass(-1) x d(-1).

Diet of the Nonindigenous Asian Swamp Eel in Tropical Ornamental Aquaculture Ponds in West-Central Florida

Abstract The nonindigenous Asian swamp eel Monopterus albus is established in west-central Florida, where it invades tropical ornamental fish production ponds. The economically valuable ornamental fish industry (US

Stress is not pain. Comment on Elwood and Adams (2015) 'Electric shock causes physiological stress responses in shore crabs, consistent with prediction of pain'

42 million in 2003) is dominated by the production of small-bodied fishes cultured at high densities in small, earthen ponds. Although introduced Asian swamp eels have been described as voracious predators of fish, to date there have been no published studies containing quantitative diet information on any of the introduced populations found in the USA. The purpose of our study was to evaluate the possible effect of nonnative Asian swamp eels on the aquaculture industry by analyzing the diets of Asian swamp eels that have invaded small ponds used for the culture of ornamental fishes. We examined 71 Asian swamp eels ranging from 94 to 864 mm in total length (TL) that were taken from ornamental aquaculture farms. Fifty-two percent lacked stomach contents; otherwise, prey were relatively small and...