New occurrence of Acantholochus australiensis (Byrnes, 1986) (Copepoda: Bomolochidae) parasitizing Lutjanus argentiventris (Peters, 1869) (Eupercaria: Lutjanidae) from the Teacapan estuary, Sinaloa, Mexico

Abstract

During a survey of parasitic copepods from the Teacapan estuary, Sinaloa, Mexico, one adult female bomolochid was collected from the nostrils of the yellow snapper, Lutjanus argentiventris (Peters, 1869). The specimen was preserved in ethanol, cleared in glycerol, and examined using light microscopy. It was identified as Acantholochus australiensis (Byrnes, 1986) based on diagnostic characters, including a 6-segmented antennule, rostral hooks, absence of modified setae on the first antennal segment, two setae on the second endopodal segment of leg 2, and exopodal segments of leg 4 equal in length. This finding represents the first record of A. australiensis from the Mexican Pacific and the first in L. argentiventris, expanding its known geographical distribution and host range, since it has only been found on sparids in Australian waters. It also represents the first report of an Acantholochus species parasitizing a lutjanid fish worldwide.