Antibiotic-resistance patterns of bacterical pathogens isolated from ornamental fish in Trinidad and Tobago

Ornamental fish farming forms an important part of the local aquaculture industry in Trinidad and Tobago, and the number of farms has been increasing annually. This study was designed to ascertain the prevalence of bacterial pathogens from fish and pond water, and determine the resistance of the bacteria to commonly used antimicrobial agents. A total of 1204 bacterial isolates were recovered: from 575 fish slurry and 111 water samples from 17 aquaculture farms. Isolates from fish were identified as belonging to 19, and those from water samples were grouped in 18 genera. The predominant genera isolated were (in descending order) Aeromonas spp., Pseudomonas spp., Plesiomonas spp., Chromobacterium spp., Enterobacter spp. and Serratia spp. Screening against 8 antimicrobial agents showed that 95.1 percent (774 of 814) of isolates from fish slurry, and 98.4 percent (254 to 258) of isolates from pond water were resistant to one or more antimicrobial agents ( P> 0.05, X2). The highest resistance (55-94 percent) were to ampicillin, oxytetracycline and erythromycin, but relatively lower resistance (4-14 percent) occurred to gentamycin and norfloxacin (P< 0.05; X2). It was concluded that the high prevalence of bacterial pathogens in ornamental fish coupled with their high levels of resistance to antimicrobial agents may pose therapeutic problems as well as health risks to farmers, workers and fish hobbyists

Connectivity of marine populations: open or closed?

Most marine populations are thought to be well connected via long-distance dispersal of larval stages. Eulerian and Lagrangian flow models, coupled with linear mortality estimates, were used to examine this assumption. The findings show that when simple advection models are used, larval exchange rates may be overestimated; such simplistic models fail to account for a decrease of up to nine orders of magnitude in larval concentrations resulting from diffusion and mortality. The alternative process of larval retention near local populations is shown to exist and may be of great importance in the maintenance of marine population structure and management of coastal marine resources.(Au)

Heavy metals, lipid peroxidation, and ciguatera toxicity in the liver of the Caribbean barracuda (Sphyraena barracuda)

Human consumption of over 400 species of tropical fish containing polyether toxins (e.g. ciguatoxins, maitotoxins) causes ciguatera fish poisoning. The Caribbean barracuda (Sphyraena barracuda) is one of the most potent ciguatoxic fish. The objective of this study was to determine whether toxicity of 14 barracuda livers was correlated with lipid peroxidation. A significant correlation (p = 0.015, Pearson's correlation) between lipid peroxidation and toxicity of barracuda liver was found. Because iron and copper are well-known catalysts of hydroxyl radical production and lipid peroxidation in biological systems, the correlation between the concentrations of these metals in barracuda liver and lipid peroxidation and toxicity was also investigated. Cadmium was significantly correlated (p = 0.014) with the toxicity of barracuda livers. This study provides the first data concerning the concentration of iron, copper, and cadmium in the liver of the Caribbean barracuda. Of the three metals studied in barracuda liver, iron was the most abundant, followed by copper and cadmium. Lipid peroxidation was highly variable and detected in five (36 percent) of the liver samples. Lipid peroxidation was not statistically significantly correlated (p > 0.05) with concentrations of iron, copper, and cadmium in barracuda liver. Collectively, these findings provide additional evidence that lipid peroxidation can be a mechanistic component of ciguatera toxicity in the Caribbean barracuda.(Au)

Ciguatera toxicity

Ciguatera poisoning is the most common foodborne illness caused by a chemical toxin in the United States and is endemic in the Caribbean and Indo-Pacific. Ciguatoxin, produced by a marine dinoflagellate that attaches to algae, is passed up the food chain to large fish and, finally, to humans. The toxin has anticholinesterase activity. The clinical picture is characterized by a variety of gastrointestinal, neurologic and cardiovascular symptoms, usually self-limited. Amitriptyline is reported to be beneficial.(AU)

Allometric growth in three species of digenetic trematodes of marine fishes from Belize

Allometric growth of body proportions and organs is determined for three species of digenetic trematodes of marine fishes from Belize: Apocreadium mexicanum Manter, 1937 (Apocreadiidae), Pseudocreadium lamelliforme (Linton 1907) Manter, 1946 (Leppocreadiidae), Paracryptogonimus americanus Manter, 1940 (Cryptogonomidae). These are compared with three other species in which allometric growth has been studied. In all species only the hindbody shows positive growth, whereas the forebody, suckers, and pharynx are consistently negative. The body width, posttesticular body, testes, and ovary are positive in some species and negative in others. In some instances the body proportion or organ is growing at the same rate as the body length (AU)

Arbovirus studies in Bush Bush Forest, Trinidad, W. I., September 1959-December 1964. IV. Vertebrate populations

An introduction has been given to the principal vertebrates of Bush Bush Forest, which include 59 species of mammal (32 of bat), 171 species of bird , 27 species of reptile, 7 species of amphibian, and an undetermined number of fish. Special attention was paid to the population dynamics, longevity, and range of small forest rodents. During the study years the populations of small rodents declined almost to the point of disappearence. (AU)

Nutrition study in British Honduras

Height-weight measurements were performed and diet questionnaires distributed to 1,649 8- and 9-year-old children in Belize city. The children were divided into three groups; Creole, Spanish extraction, and miscellaneous for specific reasons mentioned. Analysis of the height-weight measurements and returned questionnaires indicate that the diets of these children are nutritionally poor; they are much smaller than American children of the same age; and have a high incidence of colds and headaches. No consistent difference was noted with regard to the height-weight measurements of the children receiving and not receiving a CARE supplement in their schools. Height-weight measurements when compared with private school Puerto Rican children assumed receiving a good diet were consistently above British Honduran values. When compared with prewar English children receiving a poor diet and postwar English children receiving a better vitamin and mineral supplement diet, the British Honduran values were greater than those of the first group and less than those of the second. "Anemia indices" of the three ethnic groups were compared and the diferences commented on. Frequency of colds and headaches and evaluations of the health of the children by the parent were tabulated and compared for the three groups of British Honduran children.(Summary)

Poisoning by Baracuda fish

Three outbreaks of Baracuda fish poisoning are briefly described. The clinical features were gastro-intestinal, neurological and urticarial, but varied in each outbreak. No deaths occurred, treatment and prevention are discussed (AU)