RESUMO
The edible chiton Chiton articulatus is a commercially important mollusk found in the rocky intertidal zones of the Mexican tropical Pacific. Despite the intense harvesting in Acapulco Bay, Mexico, knowledge of its growth patterns is limited, hindering the development of effective management strategies. This study investigated the growth dynamics of C. articulatus using a multi-model inference approach based on size structure data collected in four sampling periods covering four decades. Results revealed continuous recruitment throughout the year, contributing to population resilience. The species exhibited growth plasticity, highlighting its adaptive potential. We found complex temporal patterns influenced mainly by climatic events. The El Niño event sowed higher growth rates and lower asymptotic length, while La Niña events showed the opposite pattern. This research provides insights into the growth dynamics of C. articulatus, highlighting the need for holistic management strategies for this commercially important species in the face of environmental change.
Assuntos
Poliplacóforos , Dinâmica Populacional , Animais , México , Poliplacóforos/fisiologia , Poliplacóforos/crescimento & desenvolvimentoRESUMO
The genus Lepidochitona (Gray 1821) contains relatively small chitons with a distinctive girdle, dorsally clothed with non-overlapping calcareous corpuscles. In the Caribbean, it is represented by four species: L. liozonis (Dall, & Simpson, 1901), L. rosea Kaas, 1972, L. rufoi García-Ríos, 2010 and L. bullocki García-Ríos, 2011. A rutinary morphological inspection of 10 specimens of a Lepidochitona species from the Florida Keys was concordant with L. liozonis (the only species of the genus informed for Florida). They did not show many morphological differences that could justify its separation from the specimens from Puerto Rico (the type locality). However, the comparison of sequences of the mitochondrial gene coding for cytochrome oxidase I (COI) of L. liozonis from Puerto Rico and the Florida specimens showed a divergence of 14%. This divergence is incompatible with a reproductively connected species. In addition to their genetic differences, the new species differs from L. liozonis in having bigger size, longer marginal spicules and a postmucronal slope very concave. Rev. Biol. Trop. 63 (2): 369-384. Epub 2015 June 01.
El género Lepidochitona (Gray, 1821) agrupa a quitones relativamente pequeños con un cinturón distintivo, por estar cubierto dorsalmente por corpúsculos calcáreos no solapados. Esta representado en el Caribe por cuatro especies: L. liozonis (Dall, & Simpson, 1901), L. rosea Kaas, 1972, L. rufoi García-Ríos, 2010 y L. bullocki García-Ríos, 2011. La inspección de una muestra de ejemplares de los cayos de la Florida permite distinguir ejemplares de lepidoquitones que podrían clasificarse como L. liozonis (la única especie del género informada para la Florida) por no presentar grandes diferencias morfológicas que justifiquen su separación de los de Puerto Rico (localidad del tipo). Sin embargo, la comparación de secuencias del gen mitocondrial que codifica para el citocromo oxidasa I (COI) de los ejemplares de la Florida con ejemplares de L. liozonis de Puerto Rico evidencia una divergencia de 14%. Esta divergencia es incompatible con especies reproductivamente conectadas. Además de sus diferencias genéticas, la nueva especie se puede distinguir de su especie gemela por ser de mayor tamaño, tener espículas marginales más largas y una pendiente posmucronal muy cóncava.
Assuntos
Poliplacóforos/anatomia & histologia , Poliplacóforos/genética , Moluscos/classificação , Porto RicoRESUMO
Eight species of polyplacophorans have been reported from La Bahia de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness) and higher diversity (Shannon's index).