Parasites from Indo‐Pacific hump‐backed dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) stranded in Hong Kong

Abstract

Between 1993 and 1998, 28 Indo-Pacific hump-backed dolphins (Sousa chinensis) and 32 finless porpoises (Neophocaena phocoenoides) stranded in Hong Kong territorial waters were examined postmortem for parasites. The nematode Halocercus pingi was discovered in the lungs of one hump-backed dolphin and in 10 finless porpoises, typically within abscesses or granulomata, and they were frequently accompanied by a catarrhal exudate and lesions characteristic of pneumonia. Seven of the 10 finless porpoises were calves with substantial lungworm infections, and three were neonates with visible fetal folds and umbilical remnants, suggesting that H pingi is transferred to the neonate before birth or during lactation. Electron micrographs of H pingi should allow the nematode to be identified by other researchers. An ectoparasitic stalked barnacle (Xenobalanus globicipitis) was recovered from a finless porpoise, the first time that this species of barnacle has been recorded in Hong Kong's territorial waters.

Neophocaena phocaenoides

“…Studies have been conducted on organochlorine levels in porpoises from Japan (Kannan et al 1989;O'Shea et al 1980), the Yangtze River (Yang et al 1988;, Yellow Sea (R. ), Bohai Sea (H. Zhang et al 1993W. Zhang, 1995), and Hong Kong (Minh et al 1999(Minh et al , 2000a(Minh et al , 2000bParsons and Chan 1998). Heavy metal levels have been evaluated for specimens from Japan (Arima and Nagakura 1979), the Yangtze River (Lui et al 1983;Yang et al 1988), Yellow Sea (R. ), Bohai Sea (Zhang et al 1995), East China Sea , and Hong Kong (Jefferson et al 2002c;Parsons 1999).…”

“…Newborn calves in Hong Kong often have high burdens of the lungworm H. pingi, suggesting that this parasite can be passed prenatally or through mother's milk ( Mortality factors for stranded finless porpoises in Hong Kong have included natural causes, such as verminous pneumonia, shark attack, and uterine infections, and human-related causes such as boat strikes and fishing net entanglement (Jefferson and Braulik 1999;Jefferson et al 2002c;Parsons and Jefferson 2000). The lungworm Halocercus pingi causes lesions in the lungs, and is often associated with verminous pneumonia (Parsons and Jefferson 2000;Parsons et al 1999Parsons et al , 2001Wu 1929). It can be so abundant in some animals that smaller respiratory passages can be nearly completely blocked (Jefferson et al 2002c).…”

Pulmonary ultrasound findings in a bottlenose dolphin Tursiops truncatus population

“…In both wild and managed dolphins, bacterial pneumonias have been reported often (Cusick & Bullock 1973, Sweeney & Ridgway 1975, Diamond et al 1979, Tangredi & Medway 1980, Howard et al 1983, Schulman et al 1997, Miller et al 1999, Dunn et al 2001, Makara et al 2007, St. Leger et al 2009), as well as fungal (Carroll et al 1968, Migaki et al 1978, Gales et al 1985, Joseph et al 1986, Schulman et al 1997, Jensen et al 1998, Reidarson et al 1998a,b, Miller et al 2002, Elad et al 2011), viral (Domingo et al. 1992, Lipscomb et al 1994a,b, 1996, Moeller 2003, Di Guardo et al 2005, Nollens et al 2008, and parasitic etiologies of pneumonia (Woodard et al 1969, Greenwood & Taylor 1977, Inskeep et al 1990, Dailey et al 1991, Parsons et al 2001, Bonar et al 2007, Kuwamura et al 2007, Fauquier et al 2009). Reports of pneumonia often included findings of pleural effusion and pulmonary abscessation.…”

Dolphins, whales and porpoises : 2002-2010 conservation action plan for the world's cetaceans

“…The greatest direct source of human-caused dolphin mortality in Hong Kong appears to be from incidental catches in fishing gear (most likely pair trawls) and vessel collisions (Jefferson 2000). Organochlorines, especially DDTs, may be compromising the health of populations in at least southern China and the Bay of Bengal Parsons and Chan 1998). Mercury levels are exceptionally high in Hong Kong dolphins (Jefferson 2000).…”

“…Vessel collisions, especially involving high-speed ferries, may be a particular problem for porpoises in Hong Kong (Parsons and Jefferson 2000). Finless porpoises in Japan have high concentrations of organochlorines, butyltins, and mercury in their tissues (Kannan et al 1989;Iwata et al 1994Iwata et al , 1995Jefferson et al 2002b), and DDT levels of porpoises in Hong Kong are among the highest recorded for cetaceans (Parsons and Chan 1998). Porpoise habitat in the Yangtze has been degraded by water development, including the Gezhouba and Three Gorges dams and about 1300 smaller dams in tributaries Smith et al 2000).…”