Marine and estuarine leeches (Hirudinida : Ozobranchidae and Piscicolidae) of Australia and New Zealand with a key to the species

Abstract

Marine leeches are sanguivorous parasites either on sea turtles (family Ozobranchidae) or on elasmobranch and teleost fishes (family Piscicolidae), with the exception of Mysidobdella, which may feed on mysid shrimp. The marine leeches of Australia and New Zealand are poorly known, especially those on teleost fishes. Collections of marine leeches from all major museums in Australia and New Zealand were examined, as well as many specimens sent to the author. Ozobranchus branchiatus and O. margoi were found on sea turtles in Australia. Seven genera and 14 species of fish leeches were found in Australia; 6 genera and 10 species of fish leeches were found in New Zealand. Two genera (Pontobdella and Branchellion) and four species (P. leucothela, P. moorei, B. australis and B. plicobranchus) occur in both Australia and New Zealand. No genus is endemic to Australia, but four species are endemic based on current records (Austrobdella bilobata, Austrobdella translucens, Trachelobdella leptocephali and Pterobdella platycephalus). Two genera (Bdellamaris and Leporinabdella) and three species (B. manteri, B. eptatreti, and L. digglesi) are endemic to New Zealand based on current records. The marine leeches of Australia and New Zealand are a mix of endemic species, those of tropical or subtropical origin, and those of subantarctic origin.

Population Genetic Structure of Marine Leech, Pterobdella arugamensis in Indo-West Pacific Region

“…Leeches have been the subject of a number of taxonomic revisions and they are now generally accepted under the order Hirudinida [ 17 ]. The specimens in this study belong to the suborder Oceanobdelliformes (traditionally accepted as Rhynchobdellida), as they are jawless and have protrusible proboscis.…”

“…The family has over 60 genera, but the specimens have been identified to the genus Pterobdella due to the observed two pairs of mycetomes and five pairs of testisacs. The former character is not known in any other genus of piscicolid leeches [ 17 ]. There are a few species accepted under this genus, which include P. abditovesiculata , P. amara Kaburaki, 1921, P. arugamensis , P. leiostomi Burreson and Thoney, 1991 and P. platycephali Ingram, 1957.…”

“…They were from Penang in Peninsular Malaysia (5 sequences) [ 10 ], Bali in Indonesia (1 sequence) [ 15 ], Hainan in China (1 sequence) [ 20 ], Borneo (specific location is not available, 1 sequence) [ 34 ] and Bandar Khamir in Iran (3 sequences) [ 22 ]. Pterobdella abditovesiculata Moore, 1952 (DQ414300; formerly known as A. abditovesiculata ) was used as an outgroup as it is a closely related species to P. arugamensis [ 17 ]. ClustalW was used to align the sequences.…”

“…A marine ectoparasitic fish leech, Z. arugamensis de Silva, 1963, which was first identified in Sri Lanka and belongs to the family Piscicolidae, can infect several teleost fish, including cultured groupers [ 12 , 13 , 14 , 15 , 16 ], by feeding on the blood of its hosts; no other marine leech species has been reported to infest groupers. However, recently, this taxonomic name has been revised to P. arugamensis [ 17 ]. Any groupers that are infested with this marine leech on their skin will rub their body on any surrounding object, which can cause injuries and ulceration on their skin, leading to secondary infection [ 18 ].…”

Leeches in the extreme: Morphological, physiological, and behavioral adaptations to inhospitable habitats

“…Most leeches are not tolerant of salt or estuarine water, however, in spite of this there are marine leeches that are primarily parasitic on teleost and elasmobranch fishes (Family Piscicolidae; Fig. 2 ) or marine and freshwater turtles (Family Ozobranchidae) ( Sawyer, 1986 ; Utevsky et al, 2019 ; Burreson, 2020 ). Colonizing the oceans, members of the Family Piscicolidae are surmised to have originated from freshwater ancestors and then in several instances, recolonized freshwaters in the Holoarctic ( Utevsky and Trontelj, 2004 ; Williams and Burreson, 2006 ).…”