Shell Lesions Associated With Emydomyces testavorans Infection in Freshwater Aquatic Turtles.

A newly described onygenalean fungus, Emydomyces testavorans, has been isolated from ulcerative shell and skin lesions of freshwater aquatic chelonians. To investigate the shell lesions associated with infection and determine if any lesional features were unique to E. testavorans, tissues from turtles housed in zoological institutions (n = 45) in the United States and free-living turtles (n = 5) submitted for diagnostic biopsy or necropsy were examined. Free-living turtles were from geographically distinct habitats in Florida (n = 1) and Washington (n = 4) at the time of sampling. Histologic shell sections were evaluated for the presence or absence of specific lesional features. Infection with E. testavorans was evaluated in all cases by screening GMS (Grocott-Gomori's methenamine silver)-stained histologic sections for the presence of morphologically consistent fungi and by quantitative PCR (polymerase chain reaction) on representative frozen tissue or formalin-fixed paraffin-embedded sections. Additionally, culture was performed for 15 cases with available fresh/frozen tissue. In total, there were 17 PCR-confirmed E. testavorans cases, 29 cases with morphologically consistent fungi on GMS-stained sections, and 21 cases of shell lesions without histologic or molecular evidence of E. testavorans infection. Epithelial inclusion cysts, defined as cystic structures within the dermis lined by keratinized stratified squamous epithelium and containing necrotic bone and keratin debris, were significantly (P < .01) associated with E. testavorans infection. Other significantly associated shell lesions included squamous metaplasia, hyperkeratosis, inflammation, and osteonecrosis (P < .05). This study identified characteristic shell lesions associated with E. testavorans infection. Further studies to prove causality are needed.

Body Growth and Rapid Hematological Development Support Breath Hold of Baby Belugas (Delphinapterus leucas) during Subice Transit.

Body size and oxygen stores in the blood and muscle set breath-hold limits in marine mammals, yet these characteristics are understudied in immature cetaceans. We examined body mass and hematology from birth through adulthood in beluga whales (Delphinapterus leucas). At birth, body mass was 8% and 6% of the maximum mass recorded for adult females and males, respectively. Body mass then increased rapidly, approaching an asymptote around 12 yr for females and 18 yr for males. Interestingly, red blood cell counts, hemoglobin content, and hematocrit levels decreased after birth; this neonatal anemia was reversed as levels increased after 2 mo postpartum. Mature levels were obtained at approximately 8, 9, and 11 mo postpartum, respectively. Neonatal mean corpuscular hemoglobin also increased with ontogeny; mature levels were achieved by approximately 13 mo after birth. In contrast, mean corpuscular volume and mean corpuscular hemoglobin concentration demonstrated a significant but subtle increase throughout ontogeny. Our results indicate that postnatal maturation was required and that maturation occurred far earlier than the age at weaning (i.e., 2-3 yr postpartum). This is atypical of marine mammals, which generally achieve mature hemoglobin levels at weaning. Hematological maturation before maternal independence undoubtedly supports the prolonged breath holds of young belugas transiting under sea ice. This assessment enhances our knowledge of cetacean physiology and provides important inputs for determining age-specific dive capacity, yielding insights into age-specific flexibility to alter underwater behaviors, as will be required for future regime shifts and disturbances.

Successful treatment of a severe case of fusariomycosis in a beluga whale (Delphinapterus leucas leucas).

An adult male beluga whale (Delphinapterus leucas leucas) was presented with a 4-cm-diameter, raised, firm nodule on the medial aspect of the left pectoral fin. A fissure developed within the center of the nodule, which formed an ulcerated cyst-like lesion. The lesion rapidly progressed in size, and, with peeling of material present within the cyst, the lesion flattened to a 36 x 25-cm cutaneous ulcer that extended into the axilla. Histopathologic features were consistent with lymphocytic and suppurative dermatitis with intralesional fungi. Fusarium solani was diagnosed by polymerase chain reaction (PCR). Fungal susceptibility testing was performed and revealed drug resistance to multiple antifungal medications tested individually and in combination therapies. Treatments used included serial surgical debridement of affected and surrounding tissue, topical application and regional infusion of various azole, and allylamine antifungals combined with either dimethyl sulfoxide or Tricide for absorption potentiation, and oral voriconazole administration. Although susceptibility testing revealed resistance to voriconazole, visible improvement of the lesion was noted after 6 weeks of oral voriconazole therapy. The voriconazole dosage was tapered based on serum levels and was administered over a 12-mo period. No local recurrence or new lesions were visible by 14 mo from first presentation.

Myxobolus albi infection in cartilage of captive lumpfish (Cyclopterus lumpus).

Myxobolus albi was diagnosed in the cartilage of captive lumpfish (Cyclopterus lumpus) from 2 public aquaria. Eleven fish were affected, with the most common clinical signs being exophthalmos and grossly visible 1- to 2-mm white to tan scleral nodules. Myxozoan cysts were identified in the cartilage of the skull, branchial arch, sclera, vertebrae, tongue, all fin insertions, and the pectoral girdle. Cysts resulted in expansile, deforming, space-occupying lesions, resulting in exophthalmos but often lacking significant tissue damage or inflammation. Once cysts ruptured, free spores elicited a mild to marked inflammatory response. Spores measured 7.5 to 9.0 µm × 3.0 to 6.0 µm and contained 2 pyriform polar capsules oriented at one pole as well as occasional 1-µm-diameter basophilic nuclei. Identification was based on spore morphology together with polymerase chain reaction and sequence comparison of 18S ribosomal DNA. Isolates had 99% similarity to M. albi.