Shell dimension-weight relationships in the blood cockle Larkinia grandis (Bivalvia: Arcidae) on the southeastern coast of the Gulf of California

Abstract

espanolEl berberecho "Larkinia grandis" es un recurso comercialmente importante en el golfo de California, pero hay poca informacion disponible acerca de esta especie. En este estudio, se evaluaron las interacciones entre el peso corporal (BW) y la longitud (SL), la altura (SH) y el ancho (SW) de la concha en una poblacion de L. grandis en el golfo de California, Mexico. Se recolectaron a mano 80 berberechos mensualmente, desde agosto de 2017 hasta julio de 2018, de cerca y/o debajo de los arboles de mangle, en la costa sureste del golfo de California. El intervalo de medidas de las conchas (SL = 142.00–44.57 mm, SH = 85.50–31.15 mm, SW = 76.56–32.03 mm) indica que la poblacion muestreada estaba dominada por especimenes adultos. Solo el coeficiente de variacion para BW exhibio alta dispersion (23%–45%). Las relaciones potenciales de BW con SL, SH y SW no fueron lineales. La interaccion mas fuerte se encontro entre BW y SW (R² = 0.934); la relacion BW–SW describio mejor el crecimiento de este arcido. Todas las relaciones entre la dimension y el peso de la concha fueron significativas (P ≤ 0.05), lo cual indica tanto crecimiento alometrico negativo (SL–SW y SH–SW) como positivo (SL–SH, BW–SL, BW–SH y BW–SW). Los valores de b oscilaron entre 0.8950, para la relacion LogSH–LogSW, y 2.6240, para la interaccion LogBW–LogSH. Esta informacion preliminar es util para desarrollar estrategias de conservacion y explotacion sostenible para esta especie de importancia economica en la region estudiada. EnglishThe blood cockle "Larkinia grandis" is a commercially important resource in the Gulf of California, but little information is available on this species. In this study, the interactions between body weight (BW) and shell length (SL), height (SH), and width ( SW) were evaluated in a L. grandis population in the Gulf of California, Mexico. Eighty cockles were hand-picked monthly from August 2017 to July 2018 near and/or under mangrove trees on the southeastern coast of the Gulf of California. The range of shell measurements (SL = 14 2.00–44.57 mm, SH = 85.50–31.15 mm, SW = 76.56–32.03 mm) indicates that the sampled population was dominated by adult specimens. Only the coefficient of variation for BW exhibited high dispersion (23%–45%). The potential relationships between BW and SL, SH, and SW were non-linear. The strongest interaction was found between BW and SW (R² = 0.934), with the BW–SW relationship best describing the growth of this ark clam. All shell dimension–weight relationships were significant (P ≤ 0.05), indicating both negative (SL–SW and SH–SW) and positive (SL–SH, BW–SL, BW–SH, and BW–SW) allometric growth. The b values ranged from 0.8950, for the LogSH–LogSW relationship, to 2.6240, for the LogBW–LogSH interaction. This preliminary information is useful for developing conservation and sustainable exploitation strategies for this species, which is of economic importance to this region.