First record of Penella filosa L. (copepoda,siphonostomaida, pennellidae) parasiting the yellowfin tuna Tunnus albacares (Bonnaterre, 1788) from the mexican pacific coast

The aim of this investigation was to describe for the first time the parasitic copepod attached to the skin of the yellowfin tuna fish Thunnus albacares (Bonnaterre, 1788) in the state of Sinaloa along the Mexican Pacific coast. Five copepods were identified as Pennella filosa L. (Copepoda: Pennellidae), members of this genus are characterized by shape, size and the length of the parasite, type of host, arrangement of cephalothoracic papillae, segmentation of the first and second antenna, and structure of the abdominal plumes among the most important. This study is significant because it is the first time that this copepod of the family Pennelidae is described parasitizing this tuna fish Thunnus albacares which is a high-valued fish species that are caught year-round by both the coastal commercial and recreational fishing in Sinaloa, Mexico. Although there are several reports worldwide, locally is a new geographical distribution area for this copepod and thus contributes to our understanding of the biology, the biodiversity and host preference of these parasites.