Loading...
Publication
Aspectos da biologia do camarão Plesionika narval (Fabricius, 1787) nos Açores
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 937.54 KB | Adobe PDF |
Advisor(s)
Abstract(s)
In this study, have been approached some aspects of the biology of Plesionika narval
(Fabricius, 1787) around Azores Islands, with the purpose of deepening biological
knowledge on the species. Data from 3 research cruises made between 1998 and 2006 in
the central group of the archipelago and Princesa Alice’s sea bank were used. These
surveys have used 5 different types of traps, some lying on the bottom and others raised
above it. The hauls were made between 50 and 1200 m depths. Data analysis, especially
significance testing, was carried out using generalised linear models (glm). P.narval
was caught between 50 and 550 m, with higher catch rates at depths shallower than 150
m. The average CPUE values depend on the type of fish-trap and depth. However, the
season of the year, as well as the area (island or sea bank) do not have a significant
effect on those values. The 6273 sampled individuals had a carapace length (CL)
between 6 and 20 mm. The average CL size of males was 13,6 mm, females 13,9 mm
and ovigerous females 14,5 mm. The b coefficient in the length-weight relationship
varies between 2,254 and 2,555. The length-weight relationship varies with sex, and
between females, with sexual condition. The sex ratio varies with the season and depth,
with a dominance of females during summer and at shallower depths. Ovigerous
females occur year round but a peak was observed between spring and summer, when
the ovigerous females are in shallow waters. The size at maturity in females was 13,5
mm CL. These results suggest a seasonal vertical migration of P.narval, possibly linked
to the spawning cycle.
Description
Dissertação mest., Biologia Marinha, Universidade do Algarve, 2008
Keywords
Teses Pescas Plesionika narval Camarão Distribuição Captura Crescimento Portugal