Morfometría comparada de los estatolitos del calamar Loligo gahi d'Orbigny, 1835 (Cephalopoda: Loliginidae) del norte de Perú e islas Falkland

Abstract

Recibido: 19 noviembre 1999; versión corregida: 14 julio 2000; aceptado: 2 noviembre 2000RESUMEN. Se analizó un total de 241 estatolitos: 141 pertenecientes a Loligo gahi del norte del Perú (70 estatolitos izquierdos y 71 derechos) correspondientes a 34 machos y 47 hembras, y 100 de las islas Falkland (50 estatolitos izquierdos y 50 derechos) correspondientes a 35 machos y 23 hembras. En cada estatolito se midió longitud total (LT), longitud del domo (LD) y longitud del rostro (LR), determinándose en cada ejemplar la longitud dorsal del manto (LM) y sexo. Las medidas se transformaron como cocientes de LM, comparándose mediante análisis discriminante. No se observaron diferencias significativas entre los estatolitos izquierdo y derecho en ambos sexos y en ambas áreas, por lo que se compararon sólo los del lado derecho. Se hallaron diferencias significativas entre machos y hembras del norte de Perú así como entre ambos sexos de las islas Falkland. También se hallaron diferencias significativas para individuos del mismo sexo entre ambas zonas. Se discute la significación de las diferencias encontradas entre los estatolitos de L. gahi del Perú e islas Falkland.Palabras claves: Loligo gahi, estatolitos, morfometría, análisis discriminante, Perú, islas Falkland. Compared morphometry of squid statoliths Loligo gahi d'Orbigny, 1835(Cephalopoda: Loliginidae) of northern Perú and Falkland islands ABSTRACT. A total of 241 statoliths were analyzed: 141 belonging to Loligo gahi from the Northern Perú (70 left statoliths and 71 right statoliths) corresponding to 34 males and 47 females, and 100 from the Falkland Islands (50 left statoliths and 50 right statoliths) corresponding to 35 males and 23 females. Total length (TL), dome length (DL) and face length (FL) were measured, determining in each specimen the mantle dorsal length (ML) and sex. The measures became quotients of ML, and were compared using discriminant analysis. Significant differences between the left statolith and the rigth statolith were not observed in either sex, reason why those of the right hand side were compared. Significant differences between males and females from the North of Perú were found as well as between both sexes from those of the Falkland Islands. There were also significant differences for individuals of the same sex between both zones. The meaning of the differences found between L. gahi statoliths from Perú and Falkland Islands are being discussed.

Size-dependent change in body shape and its possible ecological role in the Patagonian squid (Doryteuthis gahi) in the Southwest Atlantic

“…The second study used discriminant analysis to investigate the differences in statolith morphometric measurements between samples from Northern Peru and the Falkland Islands. There was significant sexual dimorphism in both regions and significant differences between regions for individuals of the same sex (Vega et al 2001). The third study found significant differences in linear morphometric body measurements between specimens collected in Peru, Southern Chile and the Falkland Islands, as well as a greater sexual dimorphism in specimens collected from Falkland Islands waters compared to the other two geographic locations (Vega et al 2002).…”

Uso de la morfometria de las mandibulas de cefalopodos en estudios de contenido estomacal

“…Es posible que la variabilidad intraespecífica de los índices tenga una componente sexual ya que el dimorfismo sexual, en las estructuras duras, entre machos y hembras, ya había sido descrito anteriormente (Bolstad, 2006;Vega, 2010;CrespiAbril et al, 2010). En este estudio, la muestra analizada incluyó ejemplares tanto de sexo masculino, como femenino, excepto en aquellos casos en los cuales se contó con un ejemplar, que con excepción de Neorossia aff.…”

Benthic community structure and organic matter variation in response to oceanographic events on the Brazilian SE inner shelf

“…In studies of trophic ecology, statoliths are found in the stomach content of predatory species of fish and cephalopods. They are used for identification purposes (Clarke and Fitch 1975;Clarke 1978;Vega et al 2001). The morphological description of statoliths allows the identification of the prey species.…”

“…The morphological description of statoliths allows the identification of the prey species. In addition, statolith morphometrics can be used to identify and compare subpopulations (Vega et al 2001;Schwarz and Perez 2007). This highlights the value of the statoliths as taxonomic tools (Clarke 1978;Brunetti and Ivanovic 1991;Flores and Garland 2002).…”