The razor surgeonfish, Prionurus laticlavius, listed on the IUCN Red List of Threatened Species under the Least Concern category, plays an important ecological role as energy regulator in reef ...communities, but it is sought by the aquarium and aquaculture industry, and also is consumed by people. This study estimated the length-weight relationship (LWR) and relative condition factor (Krel) in P. laticlavius. The equation for length-weight relationship was TW= 0.02 TL3.01 for the Overall category, and the relative condition factor was 1.28. A total of 379 fish (3-45.6 cm total length) were collected in the southwestern coast of the Gulf of California using harpoon (for large fishes) and hand net (for small fishes), of which 181 were females (20.2-45.6 cm), 137 males (20.6-43.4 cm), and 61 juveniles (3-19.5 cm). Allometric coefficient b of LWR for the Overall category suggested isometric growth (b = 3.01), positive allometric growth for juveniles (b = 3.14), and negative allometric growth for adults (2.75). Results of Krel showed higher values for females during the warm season. The population showed a good nutritional condition, mainly in the warm season. This work is the first to estimate LWR and Krel for P. laticlavius, which will inform stock assessment and the management of this species in the Gulf of California.
The successive stages of oogenesis and the changes involved in the oocyte degeneration process in the penshell Atrina maura were examined using light and transmission electron microscopy. The ovarian ...maturation process is asynchronous, as oocytes at different developmental stages can be found simultaneously. Oocytes develop from oogonia and then undergo three distinct stages of oogenesis: previtellogenesis, vitellogenesis and postvitellogenesis with mature oocytes. Atrina maura displays a solitary oogenesis type, in which follicular cells become associated with oocytes from the earliest stages of development and seem to play an integral role in vitellogenesis. The cytoplasm of vitellogenic oocytes contains numerous whorls of rough endoplasmic reticulum and Golgi bodies, suggesting that auto-synthetic vitellogenesis may occur in this species. In addition, the degeneration process of postvitellogenic oocytes triggered by a seasonal increase in water temperature (> 25°C) is described.
La forma y crecimiento de la concha de los moluscos bivalvos varía entre y dentro de cada especie, en respuesta a numerosos factores bióticos y abióticos. Se evaluaron los índices biométricos y ...relaciones morfométricas de la concha de dos poblaciones del mejillón Modiolus capax en el suroeste del Golfo de California. Se colectaron 60 mejillones de Santa Rosalía (SR) y Bahía de La Paz (LP) en cada estación anual, desde verano 2019 a verano 2020. La temperatura del agua, oxígeno disuelto, pH, profundidad y transparencia se determinaron en cada muestreo por localidad. Los mejillones de SR fueron más grandes y pesados, con la forma de su concha más compacta y convexa. Las interacciones morfométricas de las dimensiones de la concha para las dos poblaciones fueron lineales. Las relaciones de la altura/longitud y altura/ancho de la concha resultaron en un crecimiento relativo de tipo alométrico positivo, mientras que la longitud/ancho de la concha presentó alometría negativa. El mayor coeficiente de correlación se obtuvo para la interacción altura/ancho de la concha en ambas poblaciones. La interacción más fuerte en SR y LP se encontró durante invierno 2019 y otoño 2019, respectivamente. Las relaciones morfométricas para el total de las poblaciones mostraron el mismo patrón que las obtenidas por estación anual. Los resultados revelan diferencias en talla, morfología y morfometría de la concha entre las dos poblaciones de M. capax, lo que refleja una situación de estrés y/o adaptación de la especie a las condiciones de cada lugar.
Immune response of lion's paw scallop Nodipecten subnodosus (Sowerby, 1835) challenged with Vibrio alginolyticus Ramirez-Castillo, Erick Ramses(Instituto Politecnico Nacional, Baja California Sur (Mexico). Centro Interdisciplinario de Ciencias Marinas); Arellano-Martinez, Marcial(Instituto Politecnico Nacional, Baja California Sur (Mexico). Centro Interdisciplinario de Ciencias Marinas); Ceballos-Vazquez, Bertha Patricia(Instituto Politecnico Nacional, Baja California Sur (Mexico). Centro Interdisciplinario de Ciencias Marinas) ...
Wētchasān sattawaphāet,
20/Dec , Letnik:
41, Številka:
4
Journal Article
Recenzirano
Immune response of Lion's paw scallop Nodipecten subnodosus to the challenge of Vibrio alginolyticus strain APSA2 was studied through the characterization of the activity of lysosomal enzymes and ...hemocyte size and number. Samples were obtained as hemocyte lysate supernatant (HLS) and plasma, after 6 and 24 hours, and 3, 6, and 10 days after challenge. The enzymatic activity was tested by colorimetric and lysoplate assay techniques. Between sampling times, significant differences in enzymatic activity determined by the colorimetric technique were found. The enzymatic activity was significantly higher in HLS than in plasma; in addition more enzymes were detected in HLS as compared with plasma. The enzymes with higher activity were leucyl arylamidase and esterase in both, HLS and plasma. Lysozyme-like activity did not show significant differences between the sampling times. However, in plasma the lysozyme-like activity was significantly higher than in HLS, suggesting that lysozyme was released from hemocytes into plasma as a first response to the challenge. A significantly negative correlation was found between protein concentration in plasma and in HLS. Based on the findings reported here, we can affirm that hemocytes and lysosomal enzymes are two of the mechanisms that this species has to fight bacterial attacks. PUBLICATION ABSTRACT
Octopus hubbsorum is a commercially important species from the Mexican Pacific, but aspects of its reproductive biology have been scarcely studied. Several studies have investigated the macroscopic ...and histological features of the reproductive system of octopods, focusing primarily on the ovary and its maturation process, but histological descriptions of the entire reproductive system in both sexes are not available. In this study, we provide detailed morphological and histological descriptions of male and female reproductive systems of O. hubbsorum locating and characterizing each of their constituent parts. Morphological features that are different among species are highlighted, as the location of the common oviduct has not been previously reported for this species, nor the differences in the epithelium of the male reproductive system.
The ultrastructural features of the spermatogenic development and mature spermatozoa morphology of Atrina maura were investigated through transmission electron microscopy. The testis displays a ...diffuse tubular structure in which gametes develop within a concentric arrangement according to the degree of development. Within the tubules also appear Sertoli cells, which contain a large amount of lipid droplets and glycogen granules in the cytoplasm, suggesting a nutritive role in the first spermatogenesis stage (spermatogonia). Four gamete maturation stages co-occurred in the same individual: spermatogonia (4–8 μm), spermatocytes (3–4 μm) (including primary and secondary), spermatids (2.5 μm) and spermatozoa (∼ 2 μm head length). The proacrosomal vesicle and flagellum occur only until the first stages of spermiogenesis, contrasting with the early formation of both structures in spermatogonia and spermatocytes in other bivalves. In A. maura, the material in the acrosomal vesicle of mature spermatozoa shows a characteristic electron density pattern, which seems to be an exclusive taxonomic feature of the family Pinnidae. However, A. maura displayed only four mitochondria in the midpiece, contrasting with five in all other species in this family.
The lion-paw scallop Nodipecten subnodosus is a commercially important resource in the northwest of Mexico; however few studies evaluate its growth. Length of shell was used to estimate individual ...growth parameters of the lion-paw scallop from a wild population. Monthly samplings were performed from January to December 2006 in Bahia de Los Angeles on the western coast of the Gulf of California, Mexico. Morphometric relationships between total length, height, total weight, and mass weight were estimated. The number of cohorts was determined monthly using the multinomial technique based on a likelihood function. The cohort that was best represented over time was used to fit the stationary growth model of von Bertalanffy. The results indicated that this species presents negative allometric growth and showed high correlation among different morphometric measures (R2> 0.88). Length frequency distributions showed two cohorts in each sample, except from August to November when there were up to three cohorts, with greater variance in those of intermediate sizes. The growth parameters were: L=8734; = 19.06 cm, k = 0.47 year-1, t0 = -0.19 years, C = 0.38, ts = 0.37. Due to fluctuations in the growth of the species, assessments should be performed based on age-structured models to support fishery management measures for this species.
The sailfish Istiophorus platypterus is one of the most common billfish species in the Mexican Pacific. Information about its feeding habits in the coastal region of Acapulco, Guerrero is extremely ...limited. In the present study we quantified the diet of sailfish, based on captures made from March 2008 to December 2009 by the sport fishing fleet of Acapulco. We analysed a total of 561 stomachs, of which 254 contained food (45%). The size interval of examined specimens was between 101 and 212 cm postorbital length and between 15 and 47 kg total weight. In general, teleosts were the most important prey, followed by cephalopods. According to index of relative importance, the most important species in the diet were the fish Auxis thazard (63.04%) and Fistularia commersonii (6.62%), followed by the cephalopod Octopus spp. (4.58%). There were no significant differences in the diet by sex (males and females), sexual maturity (immature and mature), or by season (warm and cold seasons). In all cases the most important prey species was A. thazard. We conclude that the sailfish I. platypterus off Acapulco behaves as a specialist predator because, despite the consumption of a high number of prey items, it feeds preferentially on a reduced number of prey species that form schools, and are available and abundant in the ocean.
PDF
