Resumen de Arms regeneration in the squid Lolliguncula panamensis (Mollusca: Cephalopoda)

Sairi Sarai León-Guzmán, María del Carmen Alejo Plata

• español

  Five mature specimens (3 females and 2 males) of Lolligunucula panamensis Berry, 2011 with unusually short arms, together with 31 normal individual were captured during one fishing trip on November-December 2017 in the Gulf of Tehuantepec. This study represents the first to report for arm regeneration. Dorsal mantle length and body weight were measured from the fresh specimens. Stages of arm regeneration was determined as: frayed edge (I), smooth edge (II), growth bud appearance (III), tip emergence (IV), an tip elongation (V). In the injured arms, the surface of the arm´s tip was completely covered with skin. Those short arms were either caused by malformation or accidental loss of the tip, followed by regeneration. Arm regeneration in male L. panamensis may be an important adaptation, because the arms play an important role in grasping the female during mating in this species.

• English

  During two sampling trips carried out over the continental platform of Gulf of Tehuantepec, a total of 101 Lolliguncula panamensis Berry, 1911 were caught. Thirty mature specimens (19 females and 11 males) were found to have unusually short arms. Dorsal mantle length, arm's length, and body weight were measured from the fresh specimens. Evidence of regeneration was observed at different points along arms; these may have been the result of partial autonomies. In the injured arms, the surface of the arm's tip was wholly covered with skin. Fracture planes were found in our histological sections; the autotomized arms exhibited constricted muscle fibers in the longitudinal sections indicative of wound closing. The arms of the specimens observed were very similar to the regenerating arms of other squids. This study represents the first to report arms regeneration and hectocotylus in this squid wild-caught. These results suggest that Lolliguncula panamensis exhibit partial autotomy, and the ability to regenerate the arms. Additionally, each of the eight arms can do so, presumably during defensive interaction or mating.