Comparative performance of the mussels Perna perna and Perna viridis, cultivated at four different depths.
- Authors
- Lodeiros, C?sar; Freites, Luis
- Format
- Article
- Status
- publishedVersion
- Description
O objetivo deste estudo foi avaliar o efeito da variabilidade ambiental sobre o crescimento e a sobreviv?ncia de mexilh?es subtropicais e tropicais Perna perna e Perna viridis em quatro profundidades de cultivo no Golfo de Cariaco, durante um ciclo anual. Juvenis de P. perna (39,1?1,88 mm em comprimento de concha) e P. viridis (36,7?1,87 mm) foram semeados em cordas de nylon (3/4") e suspensos de uma jangada em 1, 3, 6 e 9 m de profundidade. A cada seis semanas, foram amostradas tr?s repeti??es de cada esp?cie em cada profundidade. Os par?metros de crescimento determinados foram: massa e comprimento de concha, massa seca dos tecidos moles, bem como incrusta??o (fouling) e as taxas de sobreviv?ncia. Temperatura, transpar?ncia, clorofila a, oxig?nio, salinidade e mat?ria org?nica e inorg?nica particulada foram registados a cada profundidade de cultura com o objetivo de relacionar crescimento e sobreviv?ncia ?s altera??es ambientais. O crescimento de ambas as esp?cies foi analisado em rela??o ao ambiente, especialmente ? influ?ncia dos alimentos e da temperatura. Um per?odo de estagna??o do crescimento de P. perna foi associado ? maior temperatura e menor biomassa de fitopl?ncton, caracter?sticas da temporada com prevalente estratifica??o da coluna de ?gua (agosto a novembro de 2007). Em contraste, o crescimento do P. viridis n?o estagnou, embora tenha sido gradual e relativamente inferior. Ao final, P. perna alcan?ou taxas de crescimento mais elevadas do que P. viridis. Poss?veis estrat?gias de cultivo para melhorar a produ??o de ambas as esp?cies de mexilh?o s?o discutidas.
This study aims to evaluate the effect of environmental variability on the growth and survival of the subtropical and tropical mussels Perna perna and Perna viridis at four different culture depths in the Gulf of Cariaco during an annual cycle. Juveniles of P. perna (39.1?1.88 mm in shell length) and P. viridis (36.7?1.87 mm) were sown on nylon ropes (3/4") and suspended from a raft at 1, 3, 6 and 9 m depths. Every six weeks, three replicates of each species were sampled (10 individuals per replicate) at each depth. Growth parameters were determined: mass and shell length, dry mass of soft tissues as well as fouling and survival rates. Temperature, transparency, chlorophyll a, oxygen, salinity and particulate organic and inorganic matter were recorded at each culture depth for the purpose of relating growth and survival to environmental change. The results show that the growth of both species was linked to the environment, especially with regard to the influence of the food and temperature. A period of stagnant growth of P. perna was associated with the higher temperature and lower phytoplankton biomass that is characteristic of the season with prevalent water column stratification (August-November 2007). By contrast, the growth of P. viridis did not stagnate, although it was gradual and relatively lower. At the end, P. perna achieved higher growth rates than P. viridis. Possible culture strategies to improve the production of both mussel species are discussed.
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592016000300249#aff2
- Publication Year
- 2016
- Language
- eng
- Topic
- CULTURE DEPTH
GROWTH
FOULING
MUSSEL
UPWELLING PERIOD
- Repository
- Repositorio SENESCYT
- Rights
- openAccess
- License
- openAccess