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Free meals on long-distance cruisers: the vampire fish rides giant catfishes in the Amazon
Jansen Zuanon
INPA-Instituto Nacional de Pesquisas da Amazônia
CPBA, Caixa Postal 478, C.E.P. 69083-970 Manaus, Amazonas, Brasil
Ivan Sazima
Departamento de Zoologia e Museu de História Natural
Instituto de Biologia, Caixa Postal 6109, Universidade Estadual de Campinas, C.E.P. 13083-970 Campinas, São Paulo, Brazil
email: isazima@unicamp.br keywords
Trichomycteridae, Paracanthopoma sp. , candiru, blood-feeding, phoresis, dispersal, Pimelodidade, Zungaro zungaro, Amazon publication date: 01-01-2005
Abstract
The trichomycterid catfishes known as candirus are renowned for their blood feeding, but information on their habits under natural conditions is very fragmentary and generally restricted to hosts or habitats. We recorded an undescribed species of the vandelliine genus Paracanthopoma riding the giant jau catfish, Zungaro zungaro (Pimelodidae), in the upper Amazon. The candirus were found on the hosts caudal and pectoral fins, as well as the base of the dorsal fin, with their snouts buried up to the eyes in the tough skin of the catfish host. All of them had small amounts of partly digested blood in the distal part of the gut. Along the hosts dorsal fin base we found a few additional tiny holes, most of them healed. We suggest that Paracanthopoma feeds on the gill chamber of its hosts, and that the individuals we found were taking a ride partly buried into the hosts skin. Our assumption seems supported by the widespread behaviour of vandelliine candirus taking blood from the gill region of their hosts, and by a report of Paracanthopoma parva found on the gills of another species of giant catfish, Brachyplatystoma vaillanti . Additionally, the Paracanthopoma sp. individuals we examined were not gorged with blood as usual for several vandelliines. Species within the genus Paracanthopoma have the longest and most robust snout, and the longest and strongest dentary teeth among blood-feeding candirus, which fit their drilling needs. Taking a ride on a giant host would be advantageous for Paracanthopoma candirus for several reasons: 1) dispersal; 2) no need to search for hosts to feed; and 3) protection from predators. The alternative explanation that Paracanthopoma takes blood from the tiny holes it drills in the skin seems unlikely, due to the recent finding that species of the genus Vandellia are unable to take blood from their hosts actively and cut open a major branchial artery to gorge themselves with blood due to the hosts arterial pressure instead. The body parts of the host the Paracanthopoma sp. individuals were attached on have no large vessels that would supply them with plenty of blood. Thus, drilling a hole on a giant host skin seems to serve mostly to anchor the Paracanthopoma candirus to their long-distance cruising catfish host. If our assumption holds true, then species of this genus exemplify an instance of phoresis (hitch-hiking) among the blood-feeding candirus. how to quote this paper
Zuanon, J. and Sazima, I. Free meals on long-distance cruisers: the vampire fish rides giant catfishes in the Amazon. Biota Neotrop. Jan/Jun 2005, vol. 5, no. 1. http://www.biotaneotropica.org.br/v5n1/en/abstract?article+BN03005012005 . ISSN 1676-0611 Cited species
Brachyplatystoma vaillanti Zungaro zungaro 