ABSTRACT:Sharks are of commercial, research, conservation, and exhibition importance but we know little regarding health parameters and population status for many species. Here we present health indicators and species comparisons for adults of three common wild-caught species: 30 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) and 31 bonnethead sharks (Sphyrna tiburo) from the western Atlantic, and 30 spiny dogfish sharks (Squalus acanthias) from the eastern Pacific. All animals were captured during June-July 2009 and 2010. Median values and preliminary reference intervals were calculated for hematology, plasma biochemistry, trace nutrients, and vitamin A, E, and D concentrations. Significant differences, attributable to physiologic differences among the species, were found in the basic hematologic and plasma biochemistry variables. Significant species differences in arsenic and selenium plasma concentrations were found and appear to coincide with diet and habitat variability among these three species. Vitamin E was significantly higher in the bonnethead shark, again related to the foraging ecology and ingestion of plant material by this species. The Atlantic sharpnose had significantly higher vitamin A concentrations, supported by the higher proportion of teleosts in the diet. Vitamin D was below the limit of quantification in all three species. These preliminary reference intervals for health variables can be used to assess and monitor the population health and serve as indicators of nutritional status in these populations of wild elasmobranchs.
Background
The microorganisms populating the gastro-intestinal tract of vertebrates, collectively known as “microbiota”, play an essential role in digestion and are important in regulating the immune response. Whereas the intestinal microbiota in humans and model organisms has been studied for many years, much less is known about the microbiota populating the intestinal tract of wild animals.
Results
The relatively large number of raptors admitted to the Tufts Wildlife Clinic on the Cummings School of Veterinary Medicine at Tufts University campus provided a unique opportunity to investigate the bacterial microbiota in these birds. Opportunistic collection of fecal samples from raptors of 7 different species in the orders Strigiformes, Accipitriformes, and Falconiformes with different medical histories generated a collection of 46 microbiota samples. Based on 16S amplicon sequencing of fecal DNA, large β-diversity values were observed. Many comparisons exceeded weighted UniFrac distances of 0.9. Microbiota diversity did not segregate with the taxonomy of the host; no significant difference between microbiota from Strigiformes and from Accipitriformes/Falconiformes were observed. In contrast, in a sample of 22 birds admitted for rehabilitation, a significant effect of captivity was found. The change in microbiota profile was driven by an expansion of the proportion of Actinobacteria. Based on a small number of raptors treated with anti-microbials, no significant effect of these treatments on microbiota α-diversity was observed.
Conclusions
The concept of “meta-organism conservation”, i.e., conservation efforts focused on the host and its intestinal microbiome has recently been proposed. The observed effect of captivity on the fecal microbiota is relevant to understanding the response of wildlife to captivity and optimizing wildlife rehabilitation and conservation efforts.
A novel Babesia species is described from blood collected from 3 common murres (also known as common guillemots) (Uria aalge) from California. This is the first report of a Babesia species from the Alcidae and the second from the Charadriiformes. Babesia uriae n. sp. is morphologically similar to several other avian Babesia species but can be differentiated from Babesia bennetti, the only other species from a host in the Charadriiformes, by size of round and amoeboid forms. Phylogenetic analysis of near-full length 18S rRNA, ITS-1, 5.8S rRNA, and ITS-2 sequences indicated that the Babesia sp. from the common murre is closely related to Babesia poelea, a parasite of brown boobies (Sula leucogaster).
In order to improve understanding of parasitism in South American pinnipeds, respiratory and gastrointestinal samples were collected from 12 Arctocephalus australis (South American fur seal), one Arctocephalus gazella (Antarctic fur seal), and one Otaria flavescens (South American sea lion). Ova and larvae were microscopically identified from fecal samples and respiratory secretions collected from live A. australis undergoing rehabilitation at Centro de Recuperação de Animais Marinhos (CRAM-FURG) in Rio Grande, Rio Grande do Sul, Brazil during June-July 2012. Adult parasites were collected from the lungs and gastrointestinal tracts of animals that died while undergoing treatment or were found dead along the southern Brazil coast. Parasites were identified by polymerase chain reaction and DNA sequencing, microscopic examination, comparison with keys, and histologic examination of tissues. Lung parasites of the Parafilaroides genus (Metastrongyloidea, Filaroididae) were identified at necropsy in both A. australis and A. gazella and gastrointestinal parasites were found in all three species of pinniped studied. Gastrointestinal parasites identified in A. australis included the nematodes Contracaecum sp. and Pseudoterranova cattani, the cestodes Adenocephalus pacificus (previously Diphyllobothrium pacificum), one from the Tetrabothridae family and one undetermined, and the acanthocephalans Corynosoma sp. and Bolbosoma sp.; from A. gazella the nematode Contracaecum sp. and the acanthocephalan Corynosoma sp.; and from O. flavescens the acanthocephalan Corynosoma sp. Ova from fecal samples from A. australis represent ascarid nematodes, Parafilaroides sp., Adenocephalus pacificus, acanthocephalans, and an egg determined either to be a trematode or pseuophyllidean cestode. With limited information surrounding parasitism, these findings are an important contribution to knowledge of the health of Southern Hemisphere pinnipeds.
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