Resumen

ACOSTA, Vanessa; PRIETO, Antulio  y  LODEIROS, Cesar. Condition index of the mussels Perna perna and Perna viridis (Bivalvia:Mytilidae) under a suspended cultivation system in the Turpialito Bay, Cariaco Gulf, Venezuela. Zootecnia Trop. [online]. 2006, vol.24, n.2, pp.177-192. ISSN 0798-7269.

With the purpose of knowing the minimum size of commercialization in fresh, it was compared the condition index of the mussels Perna perna and Perna viridis placed under a suspended cultivation system in Turpialito Bay, Gulf of Cariaco (July 2002 to 2003). Monthly, the dimension of the shell was determined as a function of the maximum ventral axis length, dry mass of the muscle, gonads, rest of soma, and the index of condition in both species. At the end of the study, P. perna presented the highest size growth (95.92 mm) compared to P. viridis (73.61 mm). The variation in weight of the dry mass was related to the condition index of both species. Perna perna showed the highest value (39.9%) in December, while P. viridis presented it in January (20.6%), coinciding in both species with an increment of the reproductive tissue and the increase of the chlorophyll a during the period of upwelling. However, the highest variability in the condition index was observed in P. viridis due to the higher intensity in the maturation processes and spawning, which was evidenced by the largest coefficient of variation (0.19). This indicates that the annual fluctuation in the reproductive process is more accentuated a typical behavior of tropical species, in spite of generating smaller reproductive tissues per unit of time than P. perna in the spawning periods.

Palabras clave : Condition index; Gulf of Cariaco; Perna perna; Perna viridis.