Talla de captura y reproducción de la langosta verde Panulirus gracilis (Decapoda: Palinuridae) en la costa de Manabí, Ecuador / Length of capture and reproduction of green spiny lobster Panulirus gracilis (Decapoda: Palinuridae) from the coast of Manabí, Ecuador

Green spiny lobster Panulirus gracilis is an economical resource of high importance for fishermen populations in the continental coast of Ecuador. Traditionally, this specie is captured using gillnets and semiautonomous diving system (hookah). With the objective to analyze some biological aspects about this fishery in Manabí, we examined lengths of capture (carapace length: CL and abdominal length: AL), sex ratio and reproductive aspects in females between June and September 2010. A total of 415 females and 288 males were captured with gillnets in El Mangle-Puerto Cayo (Central coast, depth: 3-6m), and by diving in Puerto López-Salango (South coast, depth: 7-12m). Sex ratio from males to females was 0.72:1 for gillnets, and 0.63:1 for diving. Lobsters captured by diving were larger (84.1±3.3mm CL) than lobsters captured by gillnets (73.4±2.9mm CL). Percentage of ovigerous females captured by diving was higher than females captured by gillnets. There was a pattern between lengths by sex (relation AL vs. CL); females were larger than males at same CL. Differences found between lengths and the occurrence of ovigerous females could be related with depth where capture methods are used. A total of 98% of landed lobsters were smaller than legal captured length and we recommend the establishment of a monitoring evaluation program during the fishing season, and a ban, in order to evaluate the natural fluctuation in length and reproductive stages of green spiny lobster in the coasts of Manabí.

La langosta verde Panulirus gracilis es un recurso de gran importancia económica para las poblaciones pesqueras de la costa continental del Ecuador. Esta especie es capturada tradicionalmente mediante redes y buceo semiautónomo (hookah). Para analizar algunos aspectos biológicos de la pesquería en la provincia de Manabí, se examinó la talla de captura (longitud cefalotorácica: LC y abdominal: LA), proporción sexual y aspectos reproductivos en hembras (n=415) de 703 especímenes entre junio y septiembre 2010: con red en El Mangle-Puerto Cayo (costa central, profundidad: 3-6m), y mediante buceo en Puerto López-Salango (costa centro-sur, profundidad: 7-12m). La proporción sexual: machos a hembras fue 0.72:1 para captura con red y 0.63:1 para buceo. Las langostas capturadas con buceo fueron más grandes (84.1±3.3mm LC) que las capturadas con red (73.4±2.9mm LC). La proporción de hembras ovígeras capturadas con buceo fue mayor que en las capturas con red. La diferencia entre talla y ocurrencia de hembras ovígeras podría relacionarse con la profundidad a la que los métodos de captura fueron utilizados. El 98% de las langostas analizadas estuvieron por debajo de la talla legal. Se propone el establecimiento de un programa de evaluación continua del recurso durante la temporada de pesca y veda para conocer la fluctuación natural del tamaño y época reproductiva de la langosta verde en Manabí.

Patrón reproductivo y talla media de madurez sexual de hembras de la langosta Panulirus gracilis (Decapoda: Palinuridae) en Playa Lagarto, Guanacaste, Costa Rica / Reproductive pattern and mean size of sexual maturity of female lobsters Panulirus gracilis (Decapoda: Palinuridae) in Playa Lagarto, Guanacaste, Costa Rica

The lobster P. gracilis is important as a fishery resource and also contributes to food security of fishers in coastal communities in the North Pacific of Costa Rica. Due to the importance of updating knowledge related to the reproductive pattern of this species, we analyzed 357 specimens of female lobsters caught by the fishing methods of “hookah” and lung diving, from November 2007 to October 2008 in Playa Lagarto. Furthermore, we examined the size composition by depth; monthly pattern of reproductive activity (RAI) associated with the relative increase in sea surface temperature, and also the mean size at maturity using Generalized Linear Models. Four physiological states of sexual maturity showed that females with no signs of mating or sexual maturity have a minimum mean size of 62.3mm of cephalothorax length (CL). There are characteristics of functional maturity from very small sizes ranging from 30 to 50mm CL, being the smallest berried female reported for this specie of 35.8mm CL and the highest percentage of mature females between 70 and 80mm CL. Percentages of RAI remained above 50% during the year except October and January. In addition, it observed an increase in the RAI that started from April and continued until August associated with a relative increase in temperature on March, although the correlation was not significant (r²=0.49, p>0.05). It is possible that the low mean size at maturity (70.2mm LC) for P. gracilis in this region is related to the fishing activity. It recommends the establishment of a ban in the region of at least five months (April-August) in order to protect the reproductive seasonality of the species and to promote a recruitment increase in the fishing areas.

La langosta Panulirus gracilis es importante como recurso pesquero de las comunidades costeras en el Pacífico Norte de Costa Rica. Debido a la importancia de actualizar el conocimiento relacionado con el patrón reproductivo de esta especie, se analizaron 357 especímenes de langostas P. gracilis hembras capturados mediante el buceo con compresor y el buceo a pulmón durante noviembre de 2007 a octubre del 2008 en Playa Lagarto. Se examinó la composición de las tallas por estrato de profundidad, el patrón mensual de la actividad reproductiva (IAR) asociado al aumento relativo de la temperatura superficial del océano, y además se determinó la talla media de madurez sexual utilizando Modelos Lineales Generalizados. Los cuatro estados fisiológicos de madurez sexual mostraron que las hembras sin masa espermatófora y no ovígeras, presentaron las menores tallas con una media de 62.3mm de longitud cefalotoráxica (LC). Se observaron características de madurez sexual a partir de tallas muy bajas que van desde 30 a 50mm de LC, encontrándose la menor hembra ovígera reportada para esta especie de 35.8mm de LC y el mayor porcentaje de hembras maduras entre 70 y 80mm de LC. Los porcentajes del IAR se mantuvieron por encima del 50% durante el año, con excepción de los meses de octubre y enero. Además, se observó un aumento en el IAR que inició a partir de abril y continuó hasta agosto asociado a un relativo aumento en la temperatura a partir del mes de marzo, sin embargo esta relación no fue significativa (r²=0.49, p>0.05). No se descarta que la baja talla media de madurez sexual de 70.2mm de LC para P. gracilis en esta región sea causada por las prácticas de pesca. Se recomienda que se establezca una veda en la región de cinco meses (abril-agosto) con el fin de proteger la estacionalidad reproductiva de la especie y promover un mayor reclutamiento a las áreas de pesca.

Biología pesquera de la langosta Panulirus gracilis en Playa Lagarto, Guanacaste, Costa Rica

Biology and fishery of the lobster Panulirus gracilis in Playa Lagarto, Guanacaste, Costa Rica. Panulirus gracilis is a high valuable lobster species with considerable captures along the tropical Pacific coast. In this study, I present some biological and fishery parameters described after a sample of 843 lobsters, landed in Playa Lagarto from November 2007 to October 2008. From landing records, a total of 74.9% of lobsters were below the minimum legal catch size (80mm CL). Carapace lengths were in the range of 42.8 and 143.6mm for males and 115 and 35.8mm for females. The size structure showed a wide overlapping of population segments, and a trend to increase with depth, where lung diving and “hooka” diving operations take place. Sex ratio was 1.36 M:H. The relationship between weight and LC revealed that females are heavier than males of the same size, and this difference was significant (p<0.05). The von Bertalanffy growth parameters for males and females respectively (K=0.45-0.38, LC∞=166.9-121.7) showed accelerated growth compared to other species. Males observed a higher growth rate than females. Furthermore, natural mortality (M), total mortality (Z) and fishing mortality (F) was higher in males (0.49-2.34-1.92) than in females (0.47-1.82-1.42). Recruitment was continuous for both sexes during the year, with an elevated intensity of 18.5% in July. Under the current fishing regime the population could be at risk of collapse, as indicated by the high exploitation rate (E) 0.80. Rev. Biol. Trop. 59 (2): 619-633. Epub 2011 June 01.

Los parámetros biológicos y pesqueros analizados se fundamentaron en una muestra de 843 langostas provenientes de la actividad pesquera realizada en Playa Lagarto entre noviembre del 2007 y octubre del 2008. Las longitudes cefalotoráxicas de los machos estuvo comprendida entre los 143.6 y 42.8 y 115 y 35.8mm para hembras. El 74.9% de las langostas en los desembarques estuvo por debajo de la talla mínima legal de captura (80 mm de LC). La estructura de tallas muestra un considerable solapamiento de segmentos poblacionales y el incremento de las tallas con la profundidad en donde operan las dos modalidades de pesca estudiadas: el buceo a pulmón y el buceo con compresor. La proporción de sexos obtenida fue de 1.36 M:H. La relación entre LC y peso reveló que las hembras pesan más que los machos de una misma talla y que esta diferencia fue significativa (p<0.05). Los parámetros de crecimiento de von Bertalanffy para machos y hembras respectivamente (K=0.45-0.38, LC∞=166.9-121.7) indican un crecimiento acelerado en comparación a otras especies. Los machos por su parte exhibieron una mayor tasa de crecimiento que las hembras. Además, la mortalidad natural (M), la mortalidad total (Z) y la mortalidad por pesca (F) fue más alta en machos (0.49-2.34-1.92) que en hembras (0.47-1.82-1.42). El reclutamiento para ambos sexos presentó un comportamiento continuó durante el año con un pulso de mayor intensidad en julio de 18.5%. El significativo porcentaje de langostas por debajo de la talla mínima legal permitida para la pesca evidencia fuerte presión ejercida sobre las tallas juveniles. Afirmación que es reforzada por el valor de la tasa de explotación (E) determinada de 0.80, que indica que bajo el actual régimen de pesca la población estaría en riesgo de colapso.

Natural diet of the spiny lobster, Panulirus echinatus Smith, 1869 (Crustacea: Decapoda: Palinuridae), from São Pedro and São Paulo Archipelago, Brazil / Dieta alimentar da lagosta espinhosa, Panulirus echinatus Smith, 1869 (Crustacea: Decapoda: Palinuridae), do Arquipélago São Pedro e São Paulo, Brasil

The natural diet of the spiny lobster (Panulirus echinatus) from the São Pedro and São Paulo Archipelago was determined by stomach contents analysis of sixty-eight adult lobsters collected during October 2002, March, July and August 2003. Food items were grouped by gross taxa representing 11 food categories. Analysis included a qualitative (Frequency of Occurrence of item i - FOi) and a quantitative method (Volume of item i - Vi). A Feed Index (FI = FOi x Vi / 100) proposed by Lauzanne (1975) was also used to indicate the importance of each food category (>50: dominant, 25-50: essential, 10-25: unimportant, <10: secondary). The most important food category determined by percent FOi and percent Vi, was fish, followed by crustaceans, green algae, calcareous algae, and rocks. The remaining food categories contributed to less than 30 percent of FOi and 10 percent of Vi. Although the Feed Index revealed no dominant food category in the diet of P. echinatus, fish was considered essential, crustaceans unimportant, and the remaining food categories were classified as secondary. According to the analysis, P. echinatus can be properly classified as an omnivorous and a generalist species, because it consumes a great diversity of organisms in several trophic levels. This species presents an opportunistic behaviour, feeding on the prey available at substratum. Future studies should address variations in natural diet related to sex, reproductive cycle, and seasonality.

A dieta alimentar da lagosta espinhosa, Panulirus echinatus, do Arquipélago São Pedro e São Paulo foi determinada a partir da análise de conteúdo estomacal de sessenta e oito espécimes adultos, coletados em outubro de 2002, março, julho e agosto de 2003. Os itens alimentares foram agrupados em grandes taxa, representando 11 categorias. As análises incluíram um procedimento qualitativo (Freqüência de Ocorrência do item i - FOi) e um método quantitativo (Volume do item i - Vi). Também foi utilizado o Índice Alimentar (IA= FOi x Vi / 100) proposto por Lauzanne (1975) para indicar a importância de cada categoria (>50: dominante, 25-50: essencial, 10-25: não-importante, <10: secundário). A categoria alimentar mais importante determinada pela FOi e Vi foi peixe, seguida de crustáceos, alga verde, alga calcária e rochas. As categorias alimentares restantes contribuíram com menos de 30 por cento da FOi e 10 por cento do Vi. Embora o Índice Alimentar não tenha revelado nenhum item dominante na dieta alimentar de P. echinatus, a categoria peixe foi considerada como essencial, crustáceos como não-importante e as categorias restantes foram classificadas como secundárias. De acordo com as análises, P. echinatus pode ser corretamente classificada como sendo uma espécie onívora e generalista, uma vez que se alimenta de uma grande diversidade de organismos em diferentes níveis tróficos. Esta espécie apresenta um comportamento oportunista, alimentando-se principalmente de presas disponíveis no substrato. Para estudos futuros, recomenda-se que sejam realizadas análises considerando variações da dieta alimentar associada ao sexo, ao ciclo reprodutivo e à sazonalidade.

The early phyllosoma stages of spiny lobster Panulirus echinatus Smith, 1869 (Decapoda: Palinuridae) reared in the laboratory

The early stages of the Panulirus echinatus were hatched and reared in the laboratory. Ovigerous females were captured in their habitat and carefully transported to the laboratory. Larvae were transferred in a recirculation water tank at a density of 10 larvae.L-1. The larvae were fed on Artemia and gonads of mussel Brachydonts sp. Microalgae Dunaliella viridis was added at a concentration of 150 x 10(4) cell.mL-1. Larvae and exuviae of each zoeal stage were preserved in an alcohol 70 percent + glycerin (1:1) solution. The phyllosomas moulted eight times; the intermoulting period of each instar averaged about 7 to 10 days. The main morphological changes of each appendage were described in detail, illustrated and compared with previous reports.

Os estágios iniciais de lagosta tropical Panulirus echinatus eclodiram e foram cultivados em laboratório. Fêmeas ovígeras foram capturadas em seu habitat e cuidadosamente transportadas para o laboratório. As larvas foram cultivadas em tanques de recirculação de água e alimentadas com náuplios de Artemia e gônadas mexilhão Brachydonts sp. Microalga Dunaliella viridis foi adicionada em cada tanque de cultivo na concentração de 150 x 10(4) cel.mL-1. Os filosomas mudaram oito vezes e o período de intermuda de cada instar foi de cerca de 7 a 10 dias. As principais mudanças morfológicas de cada apêndice foram descritas, ilustradas e comparadas com trabalhos anteriores.