Vertical and horizontal larval distribution of an offshore brachyuran crab, Monodaeus couchii, off the south coast of Portugal
A strong understanding of larval distribution and abundance is of major value in delineating the location and size of a breeding population of deep-sea species such as Monodaeus couchii. In this study, vertical distribution of the larvae of a brachyuran crab, M. couchii, was assessed during two week...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Consejo Superior de Investigaciones Científicas
2014-06-01
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| Series: | Scientia Marina |
| Subjects: | |
| Online Access: | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1525 |
| Summary: | A strong understanding of larval distribution and abundance is of major value in delineating the location and size of a breeding population of deep-sea species such as Monodaeus couchii. In this study, vertical distribution of the larvae of a brachyuran crab, M. couchii, was assessed during two week-long cruises conducted at the end of January 2006 and 2007 off the South Coast of Portugal. Larvae were collected by oblique plankton hauls with a Longhurst-Hardy Plankton Recorder from the surface to 300 m. Abundance and distribution of zoeae I and II were correlated during both years. For all stages, abundance decreased with depth during the day while it increased with depth at night; the larvae thus displayed reverse diel vertical migration. Abundance of zoeae I and II was correlated with chlorophyll a levels, whereas those of later stages were correlated with neither physical parameters (chlorophyll a, temperature or salinity) nor each other. An ontogenic shift in vertical distribution explained the results; earlier zoeal stages remain in the food-rich upper water column while later stages were not correlated with any physical parameters (i.e. chlorophyll a, salinity or temperature) and migrated to the bottom for settlement. |
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| ISSN: | 0214-8358 1886-8134 |