Isolation of Clostridium Perfringens type C from a Neonatal Yangtze Finless Porpoise (Neophocaena Asiaeorientalis Asiaeorientalis)

The aim of this study was to culture pathogenic bacteria from the blowhole, lung, stomach and fecal samples of a neonatal crucially endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) that died 27 days after birth. Bacteria were inoculated and representative isolates were identified through 16S rRNA gene sequence analysis. A total of three Clostridium perfringens type C strains from the fecal samples were isolated. Toxin genes, including cpa, cpb and cpb2, were detected by PCR amplification, while the etx, iap and cpe genes were absent. Biofilm formation of the three strains was examined. Only one strain was able to form a biofilm. In addition, isolates showed strong resistance against the antibiotics amikacin (3/3), erythromycin (1/3), gentamicin (3/3), streptomycin (3/3), and trimethoprim (3/3), while sensitivity to ampicillin (3/3), bacitracin (3/3), erythromycin (2/3), penicillin G (3/3), and tetracycline (3/3). The results suggested C. perfringens type C could have contributed to the death of this neonatal porpoise.

Precautionary Principle or Evidence-Based Conservation? Assessing the Information Content of Threat Data for the Yangtze Finless Porpoise

Conservation management requires evidence, but robust data on key parameters such as threats are often unavailable. Conservation-relevant insights might be available within datasets collected for other reasons, making it important to determine the information content of available data for threatened species and identify remaining data-gaps before investing time and resources in novel data collection. The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) has declined severely across the middle-lower Yangtze, but multiple threats exist in this system and the relative impact of different anthropogenic activities is unclear, preventing identification of appropriate mitigation strategies. Several datasets containing information on porpoises or potential threats are available from past boat-based and fishing community surveys, which might provide novel insights into causes of porpoise mortality and decline. We employed multiple analytical approaches to investigate spatial relationships between live and dead porpoises and different threats, reproductive trends over time, and sustainable offtake levels, to assess whether evidence-based conservation is feasible under current data availability. Our combined analyses provide new evidence that mortality is spatially associated with increased cargo traffic; observed mortality levels (probably a substantial underestimate of true levels) are unsustainable; and population recruitment is decreasing, although multiple factors could be responsible (pollutants, declining fish stocks, anthropogenic noise, reduced genetic diversity). Available data show little correlation between patterns of mortality and fishing activity even when analyzed across multiple spatial scales; however, interview data can be affected by multiple biases that potentially complicate attempts to reconstruct levels of bycatch, and new data are required to understand dynamics and sustainability of porpoise-fisheries interactions. This critical assessment of existing data thus suggests that in situ porpoise conservation management must target multiple co-occurring threats. Even limited available datasets can provide new insights for understanding declines, and we demonstrate the importance of an integrative approach for investigating complex conservation problems and maximizing evidence in conservation planning for poorly known taxa.

​The Analysis of Reproduction-related Genes Provides Insights into the Adaptive Evolution of Fecundity Traits in Yangtze Finless Porpoise

Background: Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis), is the first class protected animal in China. In order to analyze the adaptive evolution of fecundity traits in YFP, the rapidly evolving gene families of YFP were obtained. At the same time, the major genes controlling ovulation, GDF9, BMP15, FSHβ and FSHR were also analyzed. Methods: Orthofinder software was employed to search homologous genes based on protein sequence. CAFÉ software was used to obtain the expansion and contraction gene families of YFP. Then, GO terms and pathway enrichment analyses were performed using TBtools software and Swissprot database. PAML package was used to calculate Ka/Ks (i.e., ω). Evolution rate changes in the positive selected genes were examined using the GU99 process in Diverge (v3.0) program. Result: In YFP, 501 rapid expansion gene families GO enrichment results showed that the reproductive activities related pathways were mainly three significant enrichment process, participation of germline stem cells maintain androgen receptors signaling pathways regulating and male reproductive tract stem cell population to maintain. The most significant GO terms of 220 rapidly contraction gene families associated with reproductive activities mainly consisted of biological processes which were involved in positive regulation of estrogen secretion, mating and estrogen metabolic process. GDF9 and BMP15 genes exhibited purifying selection. However, significant signs of positive selection were detected in FSHR and FSHβ genes, but only FSHβ showed specific changes in the YFP lineage.