Accelerating population decline of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis)

Abstract 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.

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Population Viability Analysis of Yangtze Finless Porpoise in the Yangtze Main Steam Suggesting that a Total Ban on Productive Fishing could be Decisive

Indian Journal of Animal Research ◽

10.18805/ijar.b-1353 ◽

2021 ◽

Author(s):

Wu Bin ◽

Xu Jingen ◽

Wang Jianmin ◽

Cao Lie ◽

Wang Weiping ◽

...

Keyword(s):

Growth Rate ◽

Population Decline ◽

Population Viability Analysis ◽

Population Viability ◽

Initial Population ◽

Main Stream ◽

Baseline Scenario ◽

Finless Porpoise ◽

Yangtze Finless Porpoise ◽

Main Steam

Background: China is paying more attention to ecological systems within the Yangtze River has provided great opportunities to the conservation of the Yangtze finless porpoise (YFP). The rapid population decline of YFP in the main steam appears to have slowed, but the infrequent movement of porpoises represents a considerable threat to the long-term viability of this species in this region. We studied the population viability of YFP in the Yangtze main steam, based on published ecological and genetic information.Methods: Vortex model was used to analyze the population viability of the YFP. The simulations were started from the year 2017 when the initial population size was 445 animals in baseline scenario. We examined the population viability for the species under demographic fluctuations and conservation scenarios.Result: Baseline model showed the probability of extinction was 0.245; deterministic growth rate was -0.023; stochastic growth rate was -0.036. Sensitivity analysis showed differences in population trends between the baseline and each alternative scenario and the most sensitive parameters were the percentage of females breeding and mortality rates. Under different conservation scenarios, the population of the YFP in the main stream will increase by 11.0%-181.2% in 100 years.

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