Análisis reproductivo y morfométrico de Allopetrolisthes punctatus en la zona rocosa de Punta Los Lunes, Región de Valparaíso, Chile.
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Date
2025
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Universidad de Concepción
Abstract
La fecundidad es un parámetro clave en la biología reproductiva de los organismos marinos, ya que permite evaluar la capacidad reproductiva de una especie y su dinámica poblacional. En decápodos, la fecundidad depende de diversos factores como el tamaño corporal y las condiciones ambientales específicas de cada hábitat. Allopetrolisthes punctatus es una especie de porcelánido distribuida entre Perú y la zona centro sur de Chile, se encuentra formando densas agregaciones (2500 ind/m2) en localidades con condiciones ambientales extremas como caleta Chome, Región del Biobio. Sin embargo, existen pocos estudios sobre su biología reproductiva, y desarrollo de sus estadios tempranos de vida planctónica.
El presente estudio tuvo como objetivo estimar la fecundidad de A. punctatus de la zona rocosa de Punta Los Lunes, en el extremo norte de la Bahía de Quintero, Region de Valparaíso y compararla con lo observado por estudios previos en caleta Chome. Además, se buscó analizar la relación entre la fecundidad y la morfometría de los individuos para evaluar posibles diferencias en la capacidad reproductiva de la especie en ambas localidades y describir los estadios de desarrollo embrionario y las primeras formas de vida planctónica. También se realizó un análisis morfométrico comparativo entre hembras y machos para identificar eventuales diferencias estructurales.
Los resultados revelaron una fuerte relación entre las dimensiones del cefalotórax y del abdomen para ambos sexos. En las hembras las dimensiones del abdomen fueron los principales factores que explicaron la variabilidad morfométrica, mientras que, en los machos, la variabilidad estuvo más influenciada por el tamaño del cefalotórax, presentando diferencias notables en sus características morfométricas, lo que confirma el dimorfismo sexual en la especie. Las hembras tienen un abdomen más grande, adaptado para la incubación de los huevos, mientras que los machos presentan una mayor variabilidad en el tamaño del cefalotórax y los quelípedos, lo que podría estar relacionado con las estrategias de competencia intraespecífica.
Se observó una gran variabilidad en el número de huevos por hembra, que varió entre 27 y 5722. Sin embargo, no se encontró una relación clara entre la fecundidad y la talla, lo que sugiere que otros factores, como las condiciones ambientales y la nutrición pueden influir en la capacidad reproductiva de la especie. Al comparar con el estudio de Chome, donde la fecundidad supera los 8000 huevos, se encontraron diferencias en la dispersión de los datos de fecundidad, con una mayor variabilidad en Punta Los Lunes, lo que podría estar relacionado con diferencias en las condiciones ambientales y el estrés fisiológico. Se identificaron cuatro etapas del desarrollo embrionario en los huevos: desde la fase I, con un color rojo intenso, hasta la fase IV, cuando los embriones están completamente formados y listos para la eclosión, y se obtuvieron larvas del estadio de prezoea y zoea I.
Este estudio proporciona una comprensión más detallada de la biología reproductiva de A. punctatus, evidenciando variabilidad espacial en su fecundidad probablemente debido a la influencia de factores ambientales y diferencias morfométricas entre sexos.
Fecundity is a key parameter in the reproductive biology of marine organisms, as it allows the evaluation of a species' reproductive capacity and its population dynamics. In decapods, fecundity depends on various factors such as body size and the specific environmental conditions of each habitat. Allopetrolisthes punctatus is a species of porcelain crab distributed between Peru and the central-southern region of Chile, forming dense aggregations (2500 ind/m²) in locations with extreme environmental conditions, such as Caleta Chome, in the Biobío Region. However, there are few studies on its reproductive biology and the development of its early planktonic life stages. The aim of this study was to estimate the fecundity of A. punctatus from the rocky area of Punta Los Lunes, at the northernmost point of Quintero Bay, Valparaíso Region, and compare it with previous studies conducted in Caleta Chome. Additionally, we aimed to analyze the relationship between fecundity and the morphometry of individuals to assess potential differences in the species' reproductive capacity between both locations, and to describe the stages of embryonic development and the early planktonic life forms. A comparative morphometric analysis was also conducted between females and males to identify any structural differences. The results revealed a strong relationship between the dimensions of the cephalothorax and abdomen for both sexes. In females, the abdomen's dimensions were the main factors explaining the morphometric variability, while in males, variability was more influenced by the size of the cephalothorax, showing notable differences in their morphometric characteristics, which confirms sexual dimorphism in the species. Females have a larger abdomen, adapted for egg incubation, while males show greater variability in the size of the cephalothorax and chelae, which could be related to intraspecific competition strategies. A high variability in the number of eggs per female was observed, ranging from 27 to 5722. However, no clear relationship between fecundity and size was found, suggesting that other factors, such as environmental conditions and nutrition, may influence the species' reproductive capacity. When compared with the study from Chome, where fecundity exceeds 8000 eggs, differences in the dispersion of fecundity data were found, with greater variability in Punta Los Lunes. This may be related to differences in environmental conditions and physiological stress. Four stages of embryonic development in the eggs were identified: from phase I, with a deep red color, to phase IV, when the embryos are fully formed and ready for hatching. Larvae from the prezoea and zoea I stages were obtained. This study provides a more detailed understanding of the reproductive biology of A. punctatus, highlighting spatial variability in its fecundity likely due to the influence of environmental factors and morphometric differences between sexes.
Fecundity is a key parameter in the reproductive biology of marine organisms, as it allows the evaluation of a species' reproductive capacity and its population dynamics. In decapods, fecundity depends on various factors such as body size and the specific environmental conditions of each habitat. Allopetrolisthes punctatus is a species of porcelain crab distributed between Peru and the central-southern region of Chile, forming dense aggregations (2500 ind/m²) in locations with extreme environmental conditions, such as Caleta Chome, in the Biobío Region. However, there are few studies on its reproductive biology and the development of its early planktonic life stages. The aim of this study was to estimate the fecundity of A. punctatus from the rocky area of Punta Los Lunes, at the northernmost point of Quintero Bay, Valparaíso Region, and compare it with previous studies conducted in Caleta Chome. Additionally, we aimed to analyze the relationship between fecundity and the morphometry of individuals to assess potential differences in the species' reproductive capacity between both locations, and to describe the stages of embryonic development and the early planktonic life forms. A comparative morphometric analysis was also conducted between females and males to identify any structural differences. The results revealed a strong relationship between the dimensions of the cephalothorax and abdomen for both sexes. In females, the abdomen's dimensions were the main factors explaining the morphometric variability, while in males, variability was more influenced by the size of the cephalothorax, showing notable differences in their morphometric characteristics, which confirms sexual dimorphism in the species. Females have a larger abdomen, adapted for egg incubation, while males show greater variability in the size of the cephalothorax and chelae, which could be related to intraspecific competition strategies. A high variability in the number of eggs per female was observed, ranging from 27 to 5722. However, no clear relationship between fecundity and size was found, suggesting that other factors, such as environmental conditions and nutrition, may influence the species' reproductive capacity. When compared with the study from Chome, where fecundity exceeds 8000 eggs, differences in the dispersion of fecundity data were found, with greater variability in Punta Los Lunes. This may be related to differences in environmental conditions and physiological stress. Four stages of embryonic development in the eggs were identified: from phase I, with a deep red color, to phase IV, when the embryos are fully formed and ready for hatching. Larvae from the prezoea and zoea I stages were obtained. This study provides a more detailed understanding of the reproductive biology of A. punctatus, highlighting spatial variability in its fecundity likely due to the influence of environmental factors and morphometric differences between sexes.
Description
Tesis presentada para optar al título de Biólogo/a Marino/a.
Keywords
Fecundidad, Morfometría, Decápodos (crustáceos) Chile