Serum levels of reproductive steroid hormones in captive sand tiger sharks, Carcharias taurus (Rafinesque), and comments on their relation to sexual conflicts.

Levels of reproductively-related steroids were determined in captive male sand tiger sharks, Carcharias taurus, maintained at two institutions: SeaWorld Adventure Park Orlando and the National Aquarium in Baltimore. Sexual conflicts were absent at the former, but were documented at the latter. Serum titers of 17beta-estradiol, progesterone, testosterone, and 5alpha-dihydrotestosterone were determined via radioimmunoassay in adult male sharks from 1988 to 2000. Sampling overlap between the two institutions occurred for 3 months of the year, but steroid concentrations were compared only for April due to the occurrence of sexual conflicts in the sharks at the National Aquarium in Baltimore in that month. For April, testosterone and dihydrotestosterone were significantly higher in the SeaWorld males, and progesterone was significantly higher in the National Aquarium in Baltimore males, while estradiol was not significantly different. Steroid levels were also determined from serial samples taken monthly over 17 months from three male sharks and one female shark at the National Aquarium in Baltimore in 2001-2002 and were compared with corresponding observed sexual conflicts. The steroid levels obtained showed distinct annual hormonal cycles in the male sharks and corroborated a biennial cycle for the single serially-sampled female shark. Furthermore, the steroid levels for individual males correlated with sexual conflicts as well as their position within the male dominance hierarchy. As this species is depleted in some regions globally, insight into the steroid profile of mature sand tiger sharks is important for a greater understanding of the relationship between their reproductive physiology and behavior, and may aid in captive management and reproduction.

A novel trypanoplasm-like flagellate Jarrellia atramenti n. g., n. sp. (Kinetoplastida: Bodonidae) and ciliates from the blowhole of a stranded pygmy sperm whale Kogia breviceps (Physeteridae): morphology, life cycle and potential pathogenicity.

The successful 6 mo rehabilitation of a stranded juvenile pygmy sperm whale Kogia breviceps afforded the opportunity to study the poorly known protozoan fauna of the upper respiratory tract of cetaceans. Mucus samples were collected by holding either a petri dish or glass slides over the blowhole for 3 to 5 exhalations; preparations were examined as wet mounts, and then stained with Wrights-Giemsa or Gram stain. Blood smears were stained with Wrights-Giemsa. Unidentified spindle-shaped and unidentified broad ciliates, reported from the blowhole of the pygmy sperm whale for the first time, were seen only initially, while yeast-like organisms and bacteria were seen intermittently. Epithelial cells and white blood cells were often present in the blowhole mucus, but red blood cells were never seen. A novel trypanoplasm-like bodonid kinetoplastid biflagellate (Order Kinetoplastida) was commonly encountered in the blowhole mucus, but never in the blood. Both mature flagellates and those undergoing longitudinal binary fission were present. The elongate flagellate had a long whiplash anterior flagellum; the recurrent flagellum was attached along at least two-thirds of the body length, forming a prominent undulating membrane, and the trailing portion was short. The kinetoplast was irregularly fragmented. The flagellates were either free-swimming, or attached to host material via the free portion of the posterior flagellum. The prominent undulating membrane was characteristic of Trypanoplasma, while the fragmented kinetoplast was characteristic of some species of Cryptobia. For the novel bodonid kinetoplastid, with its unique combination of morphological features (prominent undulating membrane and fragmented kinetoplast), we propose the creation of a new genus Jarrellia. We believe this to be the first published description of a flagellate from a marine mammal, and among the first reports of a trypanoplasm-like flagellate from a warm-blooded host. We expect that a diversity of flagellates and ciliates are commonly present in the blowhole of cetaceans. Future studies on the identity of the protozoans and the health of their cetacean hosts, which are readily studied in captivity, are necessary to establish their status as commensals or parasites.

Amphibian therapeutics.

The treatment of diseases in amphibians presents unique challenges for the clinician. This article describes the basic principles in selecting and administering therapeutics, and provides drug dose rates used successfully in amphibians. The importance of proper husbandary and hygiene, as it relates to amphibian health and medical management of disease, is also emphasized.

Basic husbandry and clinical assessment of the amphibian patient.

The veterinarian presented with an amphibian patient must be prepared to assess both the animal's medical condition and its husbandry record; good health is inextricably linked to proper care and diet. This article provides the clinician with guidelines for maintaining amphibians in captivity, including information on climate control and lighting, housing and cage enrichment, and nutrition. The article also covers questions to ask when taking a history, methods of restraint, and practical advice on the equipment and techniques used to conduct a complete physical examination of the amphibian patient.

Tropical fish medicine. Copper treatments. Uses and precautions.

Copper is an old but effective treatment for fish diseases. It is now primarily used to treat acute infestations of parasites such as Amyloodinium and Cryptocaryon. Many fish are sensitive to copper and may become intoxicated at concentrations required to control pathogens. Copper concentrations in treatment tanks must be measured frequently to ensure that levels are therapeutic but not toxic. A knowledge of the solution chemistry of copper is essential in understanding how to avoid unexpected changes in copper concentrations. Factors such as pH, salinity, decorative materials, nature of the filter bed, and the type of therapeutic agent used for treatment must be considered.