New data on the distribution and size composition of the North Pacific spiny dogfish Squalus suckleyi (Girard, 1854)
The results of long-term research on the spatial and vertical distribution of the North Pacific spiny dogfish Squalus suckleyi in the North Pacific Ocean and its size composition are presented. In total, data from 7059 catches of this species were analyzed (3178 with associated capture depth). The d...
| Published in: | Progress in Oceanography |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Consejo Superior de Investigaciones Científicas
2012
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| Subjects: | |
| Online Access: | https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1314 https://doi.org/10.3989/scimar.03439.22C |
| Summary: | The results of long-term research on the spatial and vertical distribution of the North Pacific spiny dogfish Squalus suckleyi in the North Pacific Ocean and its size composition are presented. In total, data from 7059 catches of this species were analyzed (3178 with associated capture depth). The description of size composition is based on measurements of 413 specimens caught by driftnets, 328 by pelagic trawls and 722 by bottom trawls. This species was found to be most widely distributed in the North Pacific in the summer and autumn months during feeding migrations. Seasonal and long-term changes in the spatial distribution were observed. A wide distribution of S. suckleyi in the Bering Sea was recorded after the year 2000, which is likely associated with recent climate change. Occurrence of the species in the water column and near the bottom differed considerably. In the water column, the maximum number of captures was observed within the upper 25 m layer (about 90%). Near the bottom, this species was most abundant at depths less than 50 m (over 45%) and within a depth range of 101-200 m (about 50%). The catch of S. suckleyi during the daytime was considerably larger than in the night, possibly due to vertical diurnal migrations. This species was found at water temperatures ranging from 0 to 12.7°C, and maximum catches were observed at temperatures over 8°C. Size compositions of bottom and pelagic trawl catches were similar (mean length 69.1 and 68.6 cm respectively) while driftnet catches were composed of larger specimens (mean length 75.3 cm). Se presentan los resultados de un estudio a largo plazo sobre la distribución espacial y vertical y la composición de tallas de la mielga del Pacífico norte, Squalus suckleyi. Se analizó la captura de 7059 ejemplares de esta especie (de los que 3178 disponían de datos de profundidad de captura). La composición de tallas se basó en las medidas de 413 ejemplares capturados mediante redes de deriva, 328 por arrastres pelágicos y 722 por arrastres de fondo. La especie se distribuye más ampliamente en el Pacífico norte durante los meses de verano y otoño, asociada a migraciones alimentarias. Se observaron cambios estacionales y a largo plazo en la distribución espacial. En el Mar de Bering se registró una amplia distribución de S. suckleyi después de 2000, probablemente asociada a cambios climáticos recientes. La presencia de la especie en la columna de agua y cerca del fondo difiere notablemente. En la columna, el número máximo de capturas (cerca del 90%) se observó en los primeros 25 m de profundidad. Cerca del fondo, la especie fue más abundante a profundidades menores de 50 m (más del 45%) y en el rango 101-200 m (cerca del 50%). Las capturas de S. suckleyi durante el día fueron considerablemente mayores que durante la noche, posiblememente debido a migraciones verticales diurnas. La especie se registró en un rango de temperaturas de 0 a 12.7°C, y las capturas máximas se dieron por encima de 8°C. La composición de tallas de los arrastres pelágicos y de fondo fue similar (talla media de 69.1 y 68.6 cm, respectivamente), mientras que las capturas mediante redes de deriva presentaron ejemplares mayores (talla media: 75.3 cm). |
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