Baseline Health and Nutritional Parameters of Wild Sand Tigers Sampled in Delaware Bay.

Species-specific hematological reference values are essential for diagnosis and treatment of disease and maintaining overall health of animals. This information is lacking for many species of elasmobranchs maintained in zoos and aquaria, thus reducing the effectiveness of care for these animals. Descriptive statistics and reference intervals were calculated for hematocrit and complete blood cell counts, biochemistry and protein electrophoresis parameters, trace minerals, vitamins, heavy metals, reproductive hormones, and fatty acids in the blood of 153 wild Sand Tigers Carcharias taurus of both sexes and a range of sizes caught in Delaware Bay (Delaware, USA). Mean hematocrit, total white blood cell counts, lymphocyte differentials, glucose, phosphorus, amylase, and aspartate aminotransferase levels were significantly higher in juveniles than in adults. Levels of estradiol, progesterone, testosterone, and differences in selenium and eicosapentaenoic acid (a polyunsaturated fatty acid) between males and females suggest that they are important parameters for improving Sand Tiger breeding success in managed care. Finally, blood metal levels for arsenic, cadmium, lead, and mercury suggest low levels of contaminant exposure for Sand Tigers during their summer residence in Delaware Bay. The results of this study provide baseline health parameters for wild Sand Tigers that will aid in effective maintenance of aquarium animals and contribute to a greater understanding of the biology of these sharks and efforts to accomplish sustainable management of their populations.

Primary intracranial fibrosarcoma in a southern sea otter Enhydra lutris nereis.

Southern sea otters Enhydra lutris nereis, a threatened marine mammal species, face numerous environmental and infectious disease challenges in their native habitat of coastal California, USA. However, there are few published cases describing neoplasia in sea otters despite their relatively long life span when cared for in aquarium settings. An 18 yr old neutered male southern sea otter, born and raised in human care, presented with an acute onset of seizures and dull mentation. Magnetic resonance imaging of the head revealed a large, central brain lesion. After no improvement with treatment, euthanasia was elected due to a poor prognosis. Grossly, a poorly demarcated, granular, tan mass expanded the cranial meninges in the longitudinal fissure at the level of the cruciate sulcus and extended into the underlying gray matter and superficial white matter. Histologically, the mass was composed of spindle cells, forming haphazardly arranged interlacing bundles and herringbone patterns, with a high mitotic count, moderate cellular pleomorphism, and prominent vascularization. Neoplastic cells demonstrated positive immunoreactivity for vimentin and negative immunoreactivity for smooth muscle actin, factor VIII-related antigen, S100, melan-A, E-cadherin, desmin, glial fibrillary acidic protein, and cytokeratin AE1/AE3. Based on gross, histologic, and immunohistochemical findings, the mass was most consistent with a primary intracranial fibrosarcoma (PIF). PIFs are a rare neoplasm in both humans and other animals with few reports in the veterinary literature. This is the first recorded case of a PIF in a sea otter.

Right Heart Failure in an African Penguin ( Spheniscus demersus ).

A 19-year-old male African penguin ( Spheniscus demersus ) was presented with coelomic distention after a 6-week history of lethargy and decreased appetite. Results of radiographs showed loss of coelomic detail, and ultrasound and computed tomography results revealed coelomic fluid and dilated hepatic veins. Echocardiography revealed moderate right atrial enlargement. Findings were consistent with right-sided cardiac disease. Treatment with furosemide initially reduced ascites, but the clinical condition worsened weeks later and enalapril, pimobendan, and sildenafil were added to the medical therapy. At 12 weeks after presentation, results of an echocardiogram revealed persistent right atrioventricular valve regurgitation, moderate ascites, and dilation of hepatic veins. Clinical signs of right heart failure were managed through adjustments in medical therapy and coelomic fluid aspiration, but the bird died 18 weeks after initial presentation. Gross and microscopic findings were consistent with valvular insufficiency and right-sided heart failure. To our knowledge, this case is the first documented report of cardiac disease in an African penguin.

Retroperitoneal hemangiosarcoma in a common carp Cyprinus carpio: a case report.

A 7.5 kg common carp Cyprinus carpio presented with prominent localized swelling in the caudal right coelomic area, identified by ultrasound as a fluid filled mass. Fine needle aspirate (FNA) and culture results suggested a sterile seroma. Centesis removed 290 ml of serosanguinous fluid that returned within days. Recheck ultrasonography revealed a solid component within the cavity. Radiography demonstrated irregular lysis and misalignment of vertebrae adjacent to the mass, most suggestive of bacterial osteitis or neoplasia. Treatment with antibiotics followed for 2 mo but failed to resolve the lesion. Repeated radiography and ultrasonography showed progressive enlargement of the mass, with vertebral lysis and invasion characteristic of neoplasia. Ultrasound-guided FNA of the solid component of the mass was non-diagnostic. Euthanasia was elected due to the poor clinical response and primary differential of neoplasia. Post-mortem MRI and CT confirmed a retroperitoneal soft tissue mass, partially surrounded by a fluid-filled cavity, causing vertebral lysis and infiltration of the spinal canal. Expansion of the mass caused severe muscle loss and an associated elevation in creatine kinase (>120000 U l-1). Necropsy results corroborated the MRI and CT findings, revealing a retroperitoneal, multilobular, red and tan mass causing dorsal displacement of the vertebral column, with vertebral lysis, pathologic fracture and invasion of the spinal canal. Histopathologic examination revealed a locally aggressive neoplasm exhibiting multiple patterns of growth, including endothelial lined vascular channels and solid areas formed by more pleomorphic polygonal and spindle cells, consistent with hemangiosarcoma.

Chromatophoroma in a crevice kelpfish (Gibbonsia montereyensis).

A captive adult crevice kelpfish, Gibbonsia montereyensis, developed a cutaneous mass, approximately 9 × 7 mm on the right side of the head in an area of nonscaled skin. Following surgical debulking, examination of both impression smears and histologic sections of the tumor revealed a predominant population of round to spindloid to polygonal cells with a moderate amount of lightly basophilic cytoplasm. The cytoplasm was filled with round, variably-sized reddish-brown granules that often obscured the nucleus. Nuclei were round to ovoid with coarsely granular chromatin. There was minimal anisocytosis and anisokaryosis. The cytoplasmic granules in histologic sections were weakly positive by the Fontana-Masson method, and staining was eliminated with melanin bleach. Immunohistochemical staining was strongly positive with a murine monoclonal antibody for melan A. As the specificity of melan A for melanophores is not clearly defined in nonmammalian species, the tumor was examined by transmission electron microscopy. Melanophores were not detected. Instead, neoplastic cells were filled with numerous intracytoplasmic organelles with triple-limiting membranes composed of concentric lamellae; these structures were most compatible with pterinosomes, which are the pigment-containing organelles of cells called xanthophores and erythrophores. As both of these organelles are ultrastructurally indistinguishable and as kelpfish skin is known to contain both xanthophores and erythrophores, a diagnosis of a mixed pigment cell tumor or chromatophoroma was made. As the tumor was grossly reddish-brown, the possibility of a neoplastic population of only erythrophores could not be excluded. Pigment cell tumors, arising from cells of the embryonic neural crest, are common in reptiles and bony fish.

Cloning and functional characterization of Chondrichthyes, cloudy catshark, Scyliorhinus torazame and whale shark, Rhincodon typus estrogen receptors.

Sex-steroid hormones are essential for normal reproductive activity in both sexes in all vertebrates. Estrogens are required for ovarian differentiation during a critical developmental stage and promote the growth and differentiation of the female reproductive system following puberty. Recent studies have shown that environmental estrogens influence the developing reproductive system as well as gametogenesis, especially in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor-ligand interactions in Elasmobranchii, we cloned a single estrogen receptor (ESR) from two shark species, the cloudy catshark (Scyliorhinus torazame) and whale shark (Rhincodon typus) and used an ERE-luciferase reporter assay system to characterize the interaction of these receptors with steroidal and other environmental estrogens. In the transient transfection ERE-luciferase reporter assay system, both shark ESR proteins displayed estrogen-dependent activation of transcription, and shark ESRs were more sensitive to 17beta-estradiol compared with other natural and synthetic estrogens. Further, the environmental chemicals, bisphenol A, nonylphenol, octylphenol and DDT could activate both shark ESRs. The assay system provides a tool for future studies examining the receptor-ligand interactions and estrogen disrupting mechanisms in Elasmobranchii.