Asociacion entre la tasa de autofecundacion y la frecuencia de larvas malformadas en poblaciones cultivadas del ostion del norte Argopecten purpuratus (Lamarck, 1819)

Abstract

RESUMEN. El incremento de la frecuencia de malformaciones y la reducción de la viabilidad y fecundidad suelen ser las primeras manifestaciones de la depresión por consanguinidad en animales. El ostión del norte, Argopecten purpuratus (Lamarck, 1819), es una especie hermafrodita funcional con autofecundación parcial y durante la reproducción artificial puede presentar altos grados de autofecundación. En este trabajo se analizó la asociación de la tasa de autofecundación con la frecuencia de larvas malformadas y la supervivencia larval. Se desovaron adultos maduros y se recogieron separadamente los gametos femeninos del 5º pulso de liberación en adelante y los masculinos. Los ovocitos fueron fecundados con espermatozoides de otro individuo, formando familias de hermanos completos. La tasa de autofecundación se verificó por la proporción de ovocitos que entra en división en una muestra de ellos sin fecundar. La tasa de autofecundación varió entre familias de 0 a 100%, con distribución de frecuencias normal. La proporción de larvas malformadas se distribuyó al azar entre las familias analizadas, pero se correlacionó negativamente, en forma moderada pero significativa, con la tasa de autofecundación y la temperatura media del cultivo. Los datos sugieren que la autofecundación en las familias de ostiones puede favorecer una mayor homeostasis del desarrollo larval. Palabras clave: depresión por consanguinidad, pectínidos, hermafroditismo, homeostasis del desarrollo, Argopecten purpuratus. Association between self-fertilization rates and the frequency of malformed larvae in farmed populations of the northern scallop Argopecten purpuratus (Lamarck, 1819)ABSTRACT. Increased frequencies of malformations and the reduction of viability and fecundity are some of the first manifestations of inbreeding depression in animals. The northern scallop, Argopecten purpuratus (Lamarck, 1819), is a functional hermaphrodite species with partial self-fertilization. During artificial reproduction, this species may present high degrees of self-fertilization. In this work, the association between the selfing rate and the frequency of larval malformations and survival were analyzed. Mature adults were spawned, and female and male gametes were collected separately from the fifth or later spawning pulses. Oocytes were fertilized with sperm from another individual, forming families of complete siblings. Selfing rates were verified by the proportion of cleaving oocytes in a non-fertilized sample. Self-fertilization ranged from 0 to 100% among families, with a normal distribution. The proportion of malformed larvae was distributed randomly among the families analyzed, but was negatively correlated -moderately but significantly -with the selfing rate and the mean water temperature of the culture. These results suggest that self-fertilization in scallop families can favor greater homeostasis of larval development.

Assessing the genetic diversity in Argopecten nucleus (Bivalvia: Pectinidae), a functional hermaphrodite species with extremely low population density and self‐fertilization: Effect of null alleles

“…The data registered during the controlled spawning process indicate that 0%–25% of zygotes per family began spontaneous embryonic development after the gametes release, with an average of 12%, presumably due to self‐fertilization. Such levels of selfing are similar to those reported for other species of hermaphroditic mollusks, like A. purpuratus (Toro, Montoya, Martínez, Gutiérrez, & Vergara, ; Winkler & Estévez, ) and Radix balthica (7%–20%; Bürkli et al, ) under similar experimental conditions, although in A. purpuratus the selfing rates can be very variable among different females (Concha, Figueroa, & Winkler, ; Toro et al, ; Winkler & Estévez, ). In addition, the occurrence of self‐fertilization has been verified by molecular analysis of massive spawns in farmed A. irradians (Li & Li, ) and N. subnodosus (Petersen, Ibarra, Ramirez, & May, ).…”

Effect of increased <i>p</i>CO<sub>2</sub> level on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

“…It is known that other factors like self-fertilization, high egg : sperm ratio, temperature, and pollutants may cause an increase in larval deformities (Conroy et al, 1996;Spangenberg and Cherr, 1996;His et al, 1997;Krassoi et al, 1997, Concha et al, 2011Kobayashi and Kijima, 2010). It has also been reported that factors in the rearing environment such as small rearing volumes, stagnant systems, addition of antibiotics, or pulse feeding may cause larvae deformities in control groups (Kurihara et al, 2007(Kurihara et al, , 2008Talmage and Gobler, 2009Waldbusser et al, 2010;Gaylord et al, 2011;Gazeau et al, 2011).…”

Effect of increased <i>p</i>CO<sub>2</sub> on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

“…It is known that other factors like self-fertilization, high egg : sperm ratio, temperature, and pollutants may cause an increase in larval deformities (Conroy et al, 1996;Spangenberg and Cherr, 1996;His et al, 1997;Krassoi et al, 1997, Concha et al, 2011Kobayashi and Kijima, 2010). It has also been reported that factors in the rearing environment such as small rearing volumes, stagnant systems, addition of antibiotics, or pulse feeding may cause larvae deformities in control groups (Kurihara et al, 2007(Kurihara et al, , 2008Talmage and Gobler, 2009Waldbusser et al, 2010;Gaylord et al, 2011;Gazeau et al, 2011).…”