Unusual causes of fatal upper aerodigestive tract obstruction in wild bottlenose dolphins (Tursiops aduncus)

Necropsy examination of dolphins living in Gulf St Vincent, Australia is routinely undertaken to enable the evaluation of disease processes and to provide rapid medicolegal assessment of any inflicted and/or accidental injuries. Two Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) are reported to demonstrate conditions that may result in unexpected death involving upper airway compromise by quite unusual mechanisms. In the first case an adult male was found with extensive soft tissue trauma suggesting human interaction. At necropsy, death was due instead to upper airway obstruction from an impacted Slender-spined Porcupine Fish (Diodon nichthemerus) in the posterior pharynx and upper esophagus. In the second case, an adult male dolphin was found to have died, following several weeks’ illness, from upper airway obstruction due to extensive respiratory tract papillomatosis within the blowhole. Given the infectious etiology of this condition the local population will be monitored for similar lesions. These cases demonstrate rare causes of upper airway obstruction in wild dolphins that were identifiable only after detailed necropsy examination. The possibility of human involvement in the deaths could be excluded.Roger W. Byard, Ikuko Tomo, Catherine M. Kemper, Susan E. Gibbs, Mike Bossley, Aaron Machado, Mark Hil

Distribution and genetic variability of young-of-the-year greater amberjack (Seriola dumerili) in the East China Sea

We examined the distribution and genetic variability of the greater amberjack Seriola dumerili in the East China Sea (ECS) from the mitochondrial DNA (mtDNA) control region of young-of-the-year (YOY) individuals, which may reflect the genetic characteristics of the spawning population. In the years 2016 and 2017, a total of 165 YOY S. dumerili were collected from two different locations in the ECS: the southern part of the ECS, and western Japanese coast. The spawning period was estimated using otolith daily increments from a total of 67 larvae and juveniles collected in the ECS. Results from size and age distribution indicated that S. dumerili spawned near the shelf break region in the southern ECS from January to April. Phylogenetic analysis based on mtDNA sequence data showed no significant genetic differentiation among samples collected from different locations, implying S. dumerili in the ECS is mainly composed of one population. S. dumerili around the Japanese coast may be originated from the southern ECS

Population analysis of Scomberomorus cavalla (Cuvier, 1829) (Perciformes, Scombridae) from the Northern and Northeastern coast of Brazil

Scomberomorus cavalla is a pelagic fish species widely distributed on the Atlantic west coast, and a noticeable decrease in its capture level in the USA and Gulf of Mexico is occurring, compared to the levels reached by the species in the past. Likewise, in some areas of Brazil, there has been indication of over-harvesting. However, there are no molecular studies focusing on the management of such an important item. Thus, in the present study, 380 nucleotide base pairs of the mitochondrial DNA D-Loop region of samples from Macapá, Bragança, and Fortaleza were sequenced. Phylogenetic and population analyses revealed that there is only one panmitic population, and low levels of genetic variability were verified. These results, as well as the noticed over-harvesting of S. cavalla, represent very important data to determine the management of such stock in order to prevent a collapse or the risk of future extinction