October 14 - Lepeophtheirus pectoralis

Lepeophtheirus pectoralis (Müller, 1776) is a caligid copepod usually found on the body surface of the European flounder, Platichthys flesus (Linnaeus, 1758) (Teleostei: Pleuronectidae). Its relatively large body size makes it easily recognizable to any observer. As any other caligid, the parasite has the ability to move freely over the body surface of its host. Notwithstanding, it is remarkable in presenting a well-defined spatial distribution pattern on the host’s body, with the gravid females accumulating, mainly, in the inner surfaces of the pectoral fins. Indeed, this behavioral feature was in the origin of the species name. The records in the literature suggest that the parasite tends to occur with considerably regularity and high numbers on its host.

For details on the species ecology, see the papers below:
Cavaleiro, F. I. & Santos, M. J. (2007) Survey of the metazoan ectoparasites of the European flounder Platichthys flesus (Linnaeus, 1758) along the north-central Portuguese coast. Journal of Parasitology 93, 1218-1222.
Cavaleiro, F. I. & Santos, M. J. (2009) Seasonality of metazoan ectoparasites in marine European flounder Platichthys flesus (Teleostei: Pleuronectidae). Parasitology 136, 855-865.

Contributed by Francisca I. Cavaleiro & Maria J. Santos, Universidade do Porto, Faculdade de Ciências, Departamento de Biologia, Rua do Campo Alegre, s/n, FC4, 4169-007 Porto, Portugal.