Fecundity of three species of Penaeid shrimps, Penaeus monodon (Fabricius, 1798), Penaeus indicus (H. Milne-Edwards, 1837) and Penaeus japonicus (Bate, 1888) of Karachi coast, Pakistan

In order to define the period of maturity of penaeid shrimps at least three indices (fecundity, size structure and density of mature females) are required. During the present study the relationships between fecundity and total length, carapace length, ovary length, body weight and ovary weight of three species of Penaeid shrimps, Penaeus (Fenneropenaeus) indicus, Penaeus (Marsupenaeus) japonicus and Penaeus (Penaeus) monodon were found out. Samples of shrimps were collected from fish market, identified to the species level, morphometric measurements of each individual were recorded and the fecundity of each developed shrimp was estimated. The relationship between body weight and fecundity and between body length and fecundity were linear in all three species. The result indicated positive strong correlation between total length (size) and fecundity in all three species. Positive strong correlations were observed between carapace length and the fecundity, ovary length and fecundity,body weight and fecundity and ovary weight and fecundity in P. indicus and P. monodon while Penaeus japonicus showed moderate positive correlations between all mentioned morphometric parameters and fecundity. There was a strong correlation between fecundity and body length in Penaeus japonicus (r =0.880), fecundity and ovary weight in Penaeus indicus (r = 0.943) and fecundity and carapace length in Penaeus monodon (r = 0.970). The estimated fecundity of Penaeus indicus varied between 989073.36 to 1380581.565 eggs for body length range 14.4 to 20.1 cm while that of Penaeus japonicus varied between 249602.2609 to 320026.71 eggs for length range 15.4 to 19.4 cm and fecundity of Penaeus monodon, with body length range 14.4 to 21.1 cm, varied between 221271.6 to 400296.288 eggs

Densidad de mysis de Penaeus aztecus Ives, 1891 en un arrecife del suroeste del Golfo de México

Background. The Parque Nacional Sistema Arrecifal Veracruzano (PNSAV) is in the southern Gulf of Mexico and supports an important shrimp fishery based on three species of Dendrobranchiata: the brown shrimp, Penaeus aztecus, the white shrimp, P. setiferus and the pink shrimp, P. duorarum. Objective. Analyze the distribution and abundance of P. aztecus during the mysis stage and determine its relationship with environmental factors in the PNSAV. Methods. We measured temperature, salinity, and dissolved oxygen in situ. The planktonic samples from four transects were collected during cold fronts and rainy weather conditions from 2011 to 2013. Results. In rainy conditions the temperature varied from 27.49 ± 0.46 to 29.98 ± 0.02°C, salinity from 32.18 ± 0.06 to 35.40 ± 0.52, and dissolved oxygen from 3.64 ± 0.13 to 6.18 ± 0.64 mgL-1; during cold fronts the temperature varied from 23.21 ± 0.05 to 25.74 ± 0.37 °C, salinity from 34.59 ± 0.39 to 35.84 ± 0.17, and dissolved oxygen from 4.04 ± 0.06 to 6.02 ± mgL-1. The highest average density with 6,938 ± 326 mysis 100 m−3, was found during rainy season in 2011 in the southern transect nearshore, followed by 3,321 ± 339 mysis 100 m−3 in the offshoresouth-central transect during cold fronts weather conditions in 2013, and 3,056 ± 236 mysis 100 m−3 in the south-central foreshore transect during cold fronts weather condition in 2011. Conclusions. The highest density of P. aztecus during mysis stage was recorded in southward foreshore area from PNSAV, during rainy conditions and related to large values of dissolved oxygen concentrations.Antecedentes. El Parque Nacional Sistema Arrecifal Veracruzano (PNSAV) está ubicado en el sur del Golfo de México y soporta una importante pesquería de camarones basada en tres especies de Dendrobranchiata: el camarón café, Penaeus aztecus, el camarón blanco, P. setiferus y el camarón rosado, P duorarum. Objetivo. Analizar la distribución y abundancia de P. aztecus en estadio de mysis y determinar su relación con los factores ambientales en el PNSAV. Métodos. Se midió la temperatura, la salinidad y el oxígeno disuelto in situ. Se recolectaron muestras planctónicas de cuatro transectos durante frentes fríos y condiciones climáticas lluviosas de 2011 a 2013. Resultados. La temperatura varió de 27.49 ± 0.46 a 29.98 ± 0.02 °C, la salinidad de 32.18 ± 0.06 a 35.40 ± 0.52 y el oxígeno disuelto de 3.64 ± 0.13 a 6.18 ± 0.64 mgL-1 en época de lluvias. Durante los frentes fríos, la temperatura varió de 23.21 ± 0.05 a 25.74 ± 0.37 °C, la salinidad de 34.59 ± 0.39 a 35.84 ± 0.17 y el oxígeno disuelto de 4.04 ± 0.06 a 6.02 ± mgL-1. La densidad media más alta fue de 6,938 ± 326 mysis 100 m−3, que se encontró durante las lluvias en 2011 en el transecto sur, cercano a la costa, seguido por 3,321 ± 339 mysis 100 m−3 en el transecto centro-sur, costa afuera durante los frentes fríos en 2,013 y 3,056 ± 236 mysis 100 m−3 en el transecto centro-sur durante los frentes fríos en 2011, en la zona de la costa. Conclusiones. La mayor densidad de mysis de P. aztecus se registró en la zona de playa al sur del PNSAV, durante las condiciones de lluvia y se relacionó con el aumento de las concentraciones del oxígeno disuelto.&nbsp

Toxicidad de diurón, Glifosato y Paraquat en postlarvas de Potimirim mexicana (Decapoda: Caridea) de la parte sur del estuario del Río Jamapa, Veracruz, SW del Golfo de México

Background. The southern zone of the estuary of the Jamapa River, Veracruz, is a place of transition between the river and the marine environment to which sediments, compounds, and species of crustaceans are transported to the neritic zone where is the Parque Nacional Sistema Arrecifal Veracruzano. Objective. The responses of exposure of Potimirim mexicana postlarvae to diuron, glyphosate, and paraquat, as well as the relative abundance, diversity of the association of crustaceans, and values of temperature, salinity, oxygen, pH, and dissolved solids in the estuary were evaluated. Methods. Sampling was carried out with white light traps in November and March. Living Potimirim mexicana postlarvae were obtained from the samples to carry out the bioassays; the remaining individuals of the association were fixed in 70% alcohol for identification and quantification. The environmental factors were measured using a multiparameter Hanna HI 9828. Results. Dissolved oxygen was of 6-7 mgL-1, pH of 8-9, temperature of 26-27° C, total dissolved solids of 700-1,500 ppm and salinity of 0.70-16 ups. Environmental conditions permit the presence of Potimirim mexicana postlarvae. Six taxa were found: postlarvae of Macrobrachium acanthurus, M. olfersii and Potimirim mexicana, megalopae of Callinectes sapidus and Armases ricordi, and zoeae of Brachyura. Diversity ranged from 1.55 to 1.77 bits*individual-1, indicating an intermediate stability of the estuary. A total of 12,827 postlarvae of P. mexicana were obtained. The LC50 values of diuron, paraquat, and glyphosate were 5.94, 1.51, and 221.05 mgL-1, respectively. Conclusions. The values found here are consistent with those obtained by other authors for different species of crustaceans. Due to the important ecological in the food web of P. mexicana, its postlarvae can be used as sensitive test organisms in ecotoxicological studies.Antecedentes. La zona sur del estuario del río Jamapa, Veracruz, es un lugar de transición entre el río y el medio marino al que se transportan sedimentos, compuestos y especies de crustáceos hasta la zona nerítica donde se encuentra el Parque Nacional Sistema Arrecifal Veracruzano. Objetivo. Se evaluaron las respuestas de exposición de las postlarvas de Potimirim mexicana a diurón, glifosato y paraquat, así como la abundancia relativa, diversidad de asociación de crustáceos y valores de temperatura, salinidad, oxígeno, pH y sólidos disueltos en el estuario. Métodos. El muestreo se realizó con trampas de luz blanca en noviembre y marzo. De las muestras se obtuvieron postlarvas vivas de Potimirim mexicana para realizar los bioensayos; los restantes individuos de la asociación se fijaron en alcohol al 70% para su identificación y cuantificación. Los factores ambientales se midieron utilizando un multiparamétrico Hanna HI 9828. Resultados. El oxígeno disuelto fue de 6-7 mgL-1, pH de 8-9, temperatura de 26-27 ° C, sólidos disueltos totales de 700-1,500 ppm y salinidad de 0,70-16 ups. Las condiciones ambientales permiten la presencia de postlarvas de Potimirim mexicana. Se encontraron seis taxones: postlarvas de Macrobrachium acanthurus, M. olfersii y Potimirim mexicana, megalopas de Callinectes sapidus y Armases ricordi y zoeas de Brachyura. La diversidad osciló entre 1,55 y 1,77 bits*individuo-1, lo que indica una estabilidad intermedia del estuario. Se obtuvieron un total de 12,827 postlarvas de P. mexicana. Los valores de LC50 de diurón, paraquat y glifosato fueron 5.94, 1.51 y 221.05 mgL-1, respectivamente. Conclusiones. Los valores aquí encontrados son consistentes con los obtenidos por otros autores para diferentes especies de crustáceos. Debido a la importancia ecológica en la trama trófica de P. mexicana, sus postlarvas pueden usarse como organismos de prueba sensibles en estudios ecotoxicológicos

A Checklist of Benthic Amphipods (Crustacea: Peracarida) in Coral Reefs of the Protected Area Tuxpan-Lobos, Mexico, SW Gulf of Mexico

Currently, there is scarce information documenting benthic amphipod species in the Marine Protected Area Tuxpan—Lobos Coral Reef, a carbonate ecosystem in the southwestern Gulf of Mexico (GoM). Sampling to determine the biodiversity of benthic amphipods associated with several living or hard—soft bottom substrates occurred in July 2014, with 1,386 individuals collected at depths of 0.5–25 m. This study summarizes the first inventory of these benthic amphipods, and includes 64 species belonging to 30 genera, 19 families, and 3 suborders. The suborder Senticaudata was highly diverse with 36 species representing 56% of the total species. The most diverse amphipod families were Aoridae, Maeridae, Colomastigidae, Leucothoidae, Ampithoidae, and Photidae, which constitute 63% of the amphipod fauna collected. Nineteen species were characterized as dominant in the Tuxpan—Lobos coral reef system. Leucothoe ashleyae, Bemlos unicornis, Ampithoe ramondi, Elasmopus levis, E. pocillimanus, and E. rapax occurred in the highest abundance with the widest spatial distribution in this protected area. Macroalgae tufts, sponges, and coral rubble hosted the maximum amount of amphipod species. Based on the richness of amphipod species, the Tuxpan—Lobos Coral Reef system has the third highest amphipod species diversity in a coral reef ecosystem, after Alacranes and Sisal reefs, both located in the southern GoM