OSTEOLOGÍA COMPARADA DE LOS PECES LINTERNA DEL GÉNERO TRIPHOTURUS FRASER-BRUNNER, 1949 (TELEOSTEI: MYCTOPHIDAE)

Abstract

Lanternfishes of the Myctophidae family inhabit deep waters of all oceans of the world, they are considered one of the most abundant families in mesopelagic environments. Myctophid fishes are characterized by the presence of photophores in the cephalic and ventral regions of the body, their pattern and number are useful for the identification of the species. Due to the lack of information on the taxonomy of this group, the identity of its species has been confused, as is patent in the genus Triphoturus. On this basis, in this study we describe and compare the meristic and osteology of the species of this genus from the Eastern Pacific. Several specimens from the fish collections of the Centro Interdisciplinario de Ciencias Marinas (CICIMAR-IPN (CI)), Scripps Institution of Oceanography (SIO) and the Natural History Museum of Paris (MNHN) were examined. The analysis includes 69 specimens of T. nigrescens from the Indian (Mozambique) and Pacific Ocean (Mexico, Micronesia and Sumatra), in addition to 33 specimens of T. oculeus from the Southern Pacific (Peru, Ecuador and Colombia), and 112 of T. mexicanus: 51 from the Gulf of California and 61 from the California Current (between Mexico and U.S.A). The bony anatomy of the species was evaluated by means of the clearing and staining techniques. Therefore, we determined that the pattern of photophores not allowed discriminate to T. mexicanus and T. oculeus. However, three distinct forms of Triphoturus spp. were recognized on the basis on its bony anatomy: T. nigrescens is characterized by the separation of the hypural bone, the lack of a foramen in the ceratohyal, and a reduced pineal window. Likewise, a high skeletal similarity between T. mexicanus and T. oculeus was observed; however the second differs by the presence of foramen in the expansions of the last hemal spines and the urohyal and in the morphology of cartilage in the pelvic plate.