Hidrobiológica (E-Journal)
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Variación temporal del ictioplancton colectado con trampas de luz en los puertos de Chuburná y Yucalpetén, Yucatán, México
Get PDFFish larvae associated to the inlet of Yucatan, México ports of Chuburná and Yucalpeten were analyzed with light traps along an annual cycle (2009). A total of 193 fish larvae with average size of 1.5 ± 0.2 cm was captured; they represented 13 species distributed in six fish families. Eucinostomus argenteus (45.1%), Sardinella aurita (30.1%) and Harengula jaguana (7.3%) were most abundant species, together they constituted 82.5% of the captured larvae. The family Gerreidae was the most diverse, with three species. Eucinostomus argenteus was dominant in Chuburná whereas Sardinella aurita and Hrengula jaguana were so in Yucalpeten. The greatest larval abundance and diversity were recorded in Chuburna, but the greatest size average was recorded in Yucalpeten. The temporal variation of the structural components was related to the hydrologic regimen of each locality, also, fish larvae abundance was lower but similar to the reported of another coastal systems of the Yucatan Peninsula. Finally, the utilization of light traps is a complement to plankton net surveys and helps to understand the communities of coastal fish larvae.Se comparan la abundancia de larvas de peces, colectadas con trampas de luz, colocadas en las bocas de los puertos de Chuburná y Yucalpetén, Yucatán durante un ciclo anual (2009). Se capturó un total de 193 organismos con una talla promedio de 1.5 ± 0.2 cm, correspondientes a 13 especies distribuidas en seis familias de peces. Eucinostomus argenteus (45.1%), Sardinella aurita (30.1%) y Harengula jaguana (7.3%), fueron las especies con mayor abundancia al constituir el 82.5% de la fauna capturadas, mientras que la familia Gerreidae fue la más diversa, al estar presente con tres especies. Eucinostomus argenteus fue la especie dominante en Chuburná, en tanto que Sardinella aurita y Harengula jaguana lo fueron en Yucalpetén. La mayor abundancia y diversidad larvaria fue registrada en Chuburná. Los organismos con mayor talla promedio se colectaron en Yucalpetén. La variación temporal de los componentes estructurales estuvo relacionada con el régimen hidrológico de cada localidad, asimismo, la abundancia del ictioplancton fue menor, pero semejante en composición, a la reportado para otros sistemas costeros de la península de Yucatán. Se concluye que, la utilización de trampas de luz, es un complemento a la red de plancton estándar y ayudaría a conocer mejor la comunidad de larvas de peces costeros
Juvenile yield index to highlight intensive culture potential in tropical marine fish
Get PDFJuvenile seedstock availability and costs are some of the main biological aspects to be considered on species for intensive culture assessment studies, together with market importance and performance under culture conditions, especially the growth rate and yields. A juvenile yield index (JYi) is described, as one of the judgment indicator of juvenile efficiency utilization on edible size culture production of tropical marine fishes. This index is expressed as the number of juveniles required per metric ton per year, and combines fish growth rate during grow-out, survival, and commercial size at harvest. The JYi could be combined with production costs and wholesale prices, to estimate a juvenile gross profit index (JGPi), and expressed in terms of estimated gross profit per juvenile number required per ton produced per year
Reproductive aspects of the spider crab Libinia dubia under laboratory conditions
Get PDFThe present study documents some aspects of the reproductive biology of the spider crab Libinia dubia (H. Milne Edwards, 1834) in conditions of captivity. Forty males and 43 ovigerous females were collected with traps and transported to the laboratory, where they were kept in seawater tanks. Average egg count per female was 20,637 (±SD 12,683.33), with an 81% (±SD 4.62) viability until hatching. Males were larger and heavier than females. On average, females measured 69 mm in length × 59 mm in width. The equation for the linear relationship between female weight (W) and number of eggs produced per female was: Y = -10,290.03 + 242.89 X (r2 = 0.866). Egg development at a temperature of 24 ± 1 °C occurred in five stages based on coloration: stage 1 (day 1-10), bright orange; stage 2 (day 11-24), orange; stage 3 (day 25-29), gray; stage 4 (day 30-34), light gray; and stage 5 (35-37), white, visible larvae. Females spawned at least twice and were receptive to males after each spawning event, although no spermatophore transfer was observed. The adaptive capacity of L. dubia to captivity makes its use feasible in breeding under controlled conditions, suggesting that it has potential for aquaculture
New distribution ranges and records of caridean shrimps (Crustacea: Decapoda: Caridea) from the west coast of Mexico
Get PDFGeographic records are presented for 24 species of Caridea (Crustacea: Decapoda) along Pacific coast of Mexico, in the East Pacific. New records are presented for Psathyrocaris fragilis Wood-Mason, 1893 (from Peru to Mexico), Periclimenes infraspinis (Rathbun, 1902), Pontonia margarita Smith, 1869, Alpheus cristulifrons Rathbun, 1900, Alpheus umbo Kim & Abele, 1988, Automate rugosa Coutière, 1900, and Lysmata californica (Stimpson, 1866) (within the Gulf of California), and Typton hephaestus Holthuis, 1951 (from the Gulf of California to the Gulf of Tehuantepec, Mexico). Additional records are given that establish the presence of species at intermediate localities within the Gulf of California and along the southwestern coast of Mexico
Effects of diets with soybean meal on the growth, digestibility, Phosphorus and Nitrogen excretion of juvenile rainbow trout Oncorhynchus mykiss
Get PDFA feeding trial was performed to evaluate the inclusion of high levels of soybean meal as a substitute for fishmeal in diets for juvenile rainbow trout and determine the phosphorus and nitrogen excretion. Fishmeal was replaced with soybean meal at levels of 50, 75 and 100 % with an inclusion of 0.8 g of phytase per kg of diet (g kg-1 ), whereas a diet with 100% substitution was used without phytase. A commercial diet and one with 100% of fishmeal were used as controls. Diets were fed to triplicate groups of juveniles (4.12 ± 0.7 g, mean ± standard deviation) for a period of 50 days, and growth performance, P and N excretion and protein digestibility were determined at the end of this period. Data were analyzed with one-way ANOVA. The results showed that fish growth decreased when 100% of substitution was used, but diet with 75% of soybean meal did not affect growth. In addition, excretion values of P and N at this level of substitution were lower than those of the fish fed the control diets. The data suggest that diet with 75% soybean meal and 25% fishmeal might be used under practical conditions, as the growth performance observed on the juveniles fed such diet was similar to those of fish fed the commercial diet and the nutrient loading was reduced
Respiración, excreción y relación oxígeno: nitrógeno de filosomas de la langosta roja Panulirus interruptus
Get PDFThe culture of the lobster Panulirus interruptus is limited due to the lack of knowledge that allow the completion of all larval stages. This work presents data on daytime and nightime oxygen consumption and ammonia excretion in phyllosoma I and II of the red lobster Panulirus interruptus reared in the lab at 21 °C and feeding with enriched Artemia nauplii. During starvation, the oxygen consumption by larvae phyllosoma dropped from 5.29 in the first hour to 3.54 mg O2 g-1h-1 after 14 h. The postabsorptive state was achieved after 13.5 h of starvation. This observation was taken into account to use starved larvae in our study. Oxygen consumption in the daytime was significantly higher than in the nightime in both larval stages. The levels of oxygen consumption (mg O2 g-1h-1) during daytime and nightime were: 4.28 and 3.66 in phyllosoma I and; 3.8 and 3.17 in phyllosoma II, respectively. There were no significant daytime/nightime differences of ammonia excretion: phyllosoma I excreted 0.011 to 0.095 mg NH4 g-1h-1; phyllosoma II excreted 0 to 0.65 mg NH4 g-1h-1. Oxygen consumption and ammonia excretion were significantly higher in phyllosoma I than in phyllosoma II. There were no significant differences between daytime and nightime The Oxygen-Nitrogen ratios of 59.1 to 422.4 obtained in both stages suggest a catabolism ranging from utilization of equal values of proteins and lipids to utilization of lipids and carbohydrates.El cultivo de la langosta Panulirus interruptus está limitado por la ausencia de conocimientos que permitan concluir el ciclo larval con eficiencia. Este trabajo presenta resultados sobre la respiración y la excreción de larvas filosomas tempranas cultivadas en el laboratorio a 21 °C y alimentadas con nauplios de Artemia enriquecidos con microalgas Isochrysis sp. y Chaetoceros muelleri. El estado postabsortivo se obtuvo después de 13.5 horas de ayuno. Durante el ayuno, el consumo del oxígeno de las larvas disminuyó de 5.29 mg O2 g-1 h-1 en la primera hora a 3.54 mg O2 g-1 h-1 después de 14 horas. El consumo de oxígeno diurno fue significativamente mayor que el nocturno en las filosomas de los estadios I y II. Los niveles medios del consumo de oxígeno durante día y noche fueron: 4.28 y 3.66 en filosoma I, y 3.8 y 3.17 en filosoma II, respectivamente. No se encontraron diferencias significativas en la excreción de amoniaco entre el día y la noche: las filosomas I excretaron de 0.011 a 0.095 mg NH4 g-1 h-1 , y las filosomas II, de 0-0.65 mg NH4 g-1 h-1 . Las tasas de consumo de oxígeno y excreción del amoniaco fueron significativamente más altas en filosoma I que en filosoma II. No se detectaron diferencias significativas entre el día y la noche, en la relación O: N (oxígeno:nitrógeno). Las relaciones O:N de 59.1 a 422.4 obtenidas en ambas fases indican un catabolismo que va de la utilización de mezclas iguales de proteínas y lípidos a la utilización de lípidos e hidratos de carbono
Sistema urogenital de los leguados de la familia Achiridae (Pisces: Pleuronectiformes) del Golfo de México
No full textAn unique anatomical pattern of the urogenital system of the Achiridae species from the Gulf of Mexico Achirus lineatus, Trinectes maculatus and Gymnchirus txae is recognized. While the morphology of the gonads fits in the Pleuronectiformes pattern, the shape of the kidney is excluively of the Achiridae, for the development of a posterior renal lobe. This lobe and the urinary bladder occupy together the left secundary body cavity. Ovries are flattened and grow as in the rest of pleuronectiformes into the secundary body cavities, between the axial musculature and the anal pterigiophores. Testicles re small, but spermtic ducts are long. T. mculatus is the species showing more anatomical differences, due to the dorsal position of the right ovary in relation to the posterior intestinl loops, for the stright anterior edge of ovaries, for the pigmentation of the spermtic ducts and for the division in two lobes of the urinary bladder.Se reconoce un mismo patrón anatómico del sistema urogenital de las especies de lenguados de la familia Achiridae del Golfo de México, Achius lineatus, Trinectes maculatus y Gymnachirus texae. Mientras que la morfología de las gónadas corresponde al patrón del orden Pleuronectíformes, la forma del riñon es exclusiva de esta familia por desarrollar un lóbulo renal posterior, que ocupa la cavidad secundaria izquierda del cuerpo, junto con la vejiga urinaria. Los ovarios son aplanados y se extienden como en todos los Pleuronectíformes extravisceralmente en las cavidades secundarias del cuerpo, entre la musculatura axial y los pterigiófosros anales. Los testículos son pequeños y lsoc onductos espermáticos son largos. La especie que muestra mayores diferencias es T. mcultus por presentr el ovrio derecho en posición dorsl a las asas intestinales posteriores, por el carácter recto del borde anterior de los ovarios, por tener pigmentados los conductos espermáticos y por mostrar la vejiga urinaria dividida en dos lóbulos
Patrones de diversidad de ciliados del plancton en la laguna de Chautengo, Guerrero, México
Get PDFThe study of the spatial distribution of plankton diversity is important, as it contributes to gain insight about ecosystems structure and functioning. We studied the spatial organization of planktonic ciliate diversity in Chautengo lagoon, Guerrero. The objectives were 1) to identify and characterize the spatial patterns of ciliate diversity and their seasonal variability, and 2) to assess the influence of environmental factors on diversity distribution. Conditional simulation geostatistical analysis was applied to H (Shannon diversity index), computed from samples collected in 40-45 sites in the lagoon in rainy and dry seasons. The relationship between ciliate diversity and lagoonal environment was examined using principal component analysis (PCA). We identified 36 planktonic ciliate morphospecies; H ranged from 0.08 to 1.9 and was patchily distributed. PCA indicated that ciliate diversity changed according to the seasons and the hydrodynamics of the sand bar opening and closing. In the rainy season, when the sand bar was open, a higher spatial heterogeneity was prevalent, with many smaller patches (1.6 km) dominated by the phototrophic Myrionecta rubra. In contrast, during the dry season and when the sand bar was closed, two larger diversity patches (2.7 km) prevailed and the dominant ciliates were Lohmanniella oviformis and Tintinnopsis sp. The impact of the patchily distributed ciliate diversity on the food webs is discussed.El estudio de la distribución espacial de la diversidad del plancton contribuye al conocimiento de la estructura y el funcionamiento de los ecosistemas. Se estudió la organización espacial de la diversidad de ciliados del plancton en la laguna de Chautengo, Guerrero, con los objetivos de: 1) identificar y caracterizar los patrones espaciales de diversidad de ciliados y su variación estacional, y 2) evaluar la influencia de factores ambientales sobre la diversidad. Se aplicó un análisis geoestadístico de simulación condicional a los valores de H (índice de diversidad de Shannon), calculados a partir de muestras recolectadas en 40-45 sitios de la laguna durante las épocas de lluvias y de secas. Las interrelaciones entre la diversidad de ciliados y el ambiente lagunar se evaluaron usando un análisis de componentes principales (ACP). Se identificaron 36 morfoespecies de ciliados pláncticos; H varió entre 0.08 y 1.9 y se distribuyó en manchones. El ACP indica que la diversidad de ciliados cambió estacionalmente y en función de las características hidrodinámicas derivadas de la apertura y cierre de la boca lagunar. Durante la temporada de lluvias y cuando la barra estuvo abierta, se presentó una mayor heterogeneidad espacial con numerosos manchones de diversidad de menor extensión (1.6 km), en los cuales dominó el ciliado fototrófico Myrionecta rubra. En contraste, en temporada de secas y cuando la boca de la laguna permaneció cerrada, se encontraron dos manchones de diversidad de mayor tamaño (2.7 km), en los que dominaron Lohmanniella oviformis y Tintinnopsis sp. Se discute el impacto sobre las redes tróficas de la distribución en manchones de la diversidad de ciliados
Nueve nuevos registros de diatomeas bentónicas de los géneros Climaconeis, Cocconeis, Licmophora, Talaroneis, Oestrupia, Petroneis y Synedrosphenia en la costa norte de la Península de Yucatán, México
Get PDFThe ecology and floristics of the marine benthic diatoms are barely studied in Mexico. For the Yucatán Península, there are practically no studies dealing with these topics. The objective of this study is to present new records of benthic diatoms and their distribution in the northern coast of the Yucatán Península; descriptions based on light and electron microscopy are also provided. In order to achieve this, we examined phytoplankton samples from various localities and from Thalassia testudinum blades on Dzilam de Bravo. With the exception of Synedrosphenia cuneata and Cocconeis maxima the remainder species were found both on phytoplankton and T. testudinum samples, thus suggesting that re-suspension processes of benthic diatoms are occurring in the area. The most abundant species was Climaconeis aff. coxii. The number of new records from a few samples emphasizes the need to continue and intensify the study of benthic diatoms in the Yucatán Península.En México la florística y ecología de las diatomeas bentónicas marinas han sido escasamente estudiadas. Para la Península de Yucatán prácticamente no existen trabajos que aborden dichos tópicos. El objetivo de este estudio es dar a conocer nuevos registros de diatomeas bentónicas y su distribución en la costa norte de la Península de Yucatán, proporcionando sus descripciones con base en observaciones de microscopía óptica y electrónica. Para ello, se revisaron muestras de fitoplancton costero obtenidas en diez localidades, así como de diatomeas epífitas sobre Thalassia testudinum en Dzilam de Bravo. Con excepción de Synedrosphenia cuneata y Cocconeis maxima, que solo aparecieron sobre T. testudinum, las especies se encontraron tanto sobre T. testudinum como en la columna de agua. Esto sugiere que ocurren procesos de resuspensión de diatomeas béntonicas en el área. La especie con mayor abundancia fue Climaconeis aff. coxii. La cantidad de nuevos registros en este trabajo a partir de un reducido número de muestras, enfatiza la necesidad de continuar e intensificar el estudio de las diatomeas bentónicas de la Península de Yucatán
Adiciones a la taxonomía de Brachionus josefinae (Rotifera: Monogononta: Brachionidae)
Get PDFIn the state of Aguascalientes, Mexico, we found a rotifer of the genus Brachionus, B. josefinae, belonging to urceolaris group. This endemic rotifer, has not yet been reported in any other region of Mexico or the America. For the first time since it was described, morphological features are displayed with images showing the ultrastructure of the habitus and the trophi, using scanning electron microscopyEn el estado de Aguascalientes, México, se encontró un rotífero del género Brachionus, B. josefinae, perteneciente al grupo urceolaris. Este rotífero endémico, aún no ha sido reportado en alguna otra región de México o del continente Americano. Por primera vez desde que fue descrito, se presenta nueva información sobre su morfología mediante imágenes que muestran la ultraestructura del hábito y del trofi, utilizando microscopía electrónica de barrido