Life history traits of the invasive estuarine shrimp Palaemon macrodactylus (Caridea: Palaemonidae) in a marine environment (Mar del Plata, Argentina).

MARÍA GUADALUPE VÁZQUEZ; CLAUDIA CRISTINA BAS; EDUARDO DANIEL SPIVAK

SCIENTIA MARINA

INST CIENCIAS MAR BARCELONA

Lugar: Barcelona; Año: 2012 vol. 76 p. 507 - 516

0214-8358

The invasive oriental shrimp Palaemon macrodactylus has been extensively recorded around the world, mainly in estuarine zones. In this work, the life history of this species was studied in Mar del Plata harbor (Argentina), a fully marine area where a stable and dense population has been established. Growth, sex proportion, morphological relationships, size at maturity and reproductive cycle were analyzed between March 2007 and March 2009. A total of 9 and 7 modal classes (M1-M9) were detected in the size frequency distributions of females and males, respectively. The modes of both sexes were the same until M4 but from M5 to M7 females were larger than males. The life span was about 1 year with a clear seasonal growth. Recruitment and reproductive periods were registered between December-March and October-March, respectively. The total sex ratio was biased to females. Nevertheless, a clear predominance of males was observed in classes smaller than 5.25 mm CL. Females reached maturity at a larger size in spring/early summer (October?January) than in late summer (February-March); the estimated sizes for 50% sexual maturity were 6.79 mm and 5.91 mm CL, respectively. The results showed great differences with a presumably native estuarine population (Japan), such as shorter life span, smaller maximum size and smaller size at maturity.