Population biology of shrimp Artemesia longinaris (Crustacea: Decapoda: Penaeidae) from the southern coast of Brazil

Abstract

Size at morphological sexual maturity, sex-ratio, and the seasonal variation in abundance of the shrimp Artemesia longinaris Bate, 1888 were assessed off Pinheira Beach, Palhoça, Santa Catarina southern Brazil. Shrimp were collected monthly from November 2003 through to October 2004, in two areas that are customarily used by local traditional fishermen (27852 0 -27851 0 S and 48833 0 -48829 0 W). Of the total of 1099 specimens measured, 23.93% were males and 76.07% females. Mean size at first maturity (LM 50 ) was estimated as 56.38 mm total length (TL) for males, and 70.34 mm TL for females. Females were significantly larger than males. Abundance of juveniles varied seasonally. A high predominance of juveniles in the areas sampled occurred in winter for both sexes, and in spring for females. In the summer and autumn, we observed a decrease in juveniles in both areas, mainly, area II. We suggest that the differential migration pattern of sexes during the reproductive cycle was the principal reason for the larger catch of females. The classical paradigm of continuous reproduction at lower latitude, with increased seasonality of the breeding period at higher latitudes, seems to apply to this species.

Population biology of the commercially exploited shrimp Artemesia longinaris (Decapoda: Penaeidae) in an upwelling region in the Western Atlantic: comparisons at different latitudes

“…Generally, female size values on maximum CL, mean CL, and CL at maturity were similar to the ones found by Semensato and Di Beneditto (2008) in Farol de São Tomé, a region of same latitude as the study area (22° S). The values were higher than those found by Castilho et al (2007b), Costa et al (2010) and Dumont and D'Incao (2008), in the latitudes of 23° S, 27° S and 32° S, respectively. However, at higher latitudes of South American (Argentina) those values become higher again, according to Castilho et al (2007a) (37° S) and Boschi and Mistakidis (1966) (43° S) (Table 3).…”

“…Boschi (1969a) and Gavio and Boschi (2004), in Mar del Plata (Argentina) and Nascimento (1981) and Ruffino and Castello (1992), in Rio Grande do Sul (Brazil), also found a predominance of females in A. longinaris populations. This pattern might be due to higher mortality of the male population (Boschi, 1969a;Cha et al, 2002), easier capture of females because of their larger size (Cha et al, 2002;Costa et al, 2010), longer foraging times of females to meet the feeding needs associated with gonadal maturation (Kevrekidis and Thessalou-Legaki, 2006). In addition, Costa et al (2010) suggested a distinct migratory pattern of A. longinaris between sexes during the reproductive cycle, which would be the mating taking place in deep waters with adult female subsequent migration to coastal waters for spawning.…”

“…However, the number of studies on population biology of this species is increasing in Brazil, emphasizing the studies of Nascimento (1981) and Ruffino and Castello (1992). Recently, mainly in Rio de Janeiro, São Paulo, and Santa Catarina States, information about population, breeding dynamics (Castilho et al, 2007a, b;Semensato and Di Benedito, 2008;Costa et al, 2010), and ecological distribution Costa et al, 2005) have been obtained and these authors state that longevity, size at onset of sexual maturity and maximum carapace length increase at higher latitudes. According to Castilho et al (2007b) reproduction and juvenile recruitment on the coast of São Paulo (tropical = 23°S) are continuous, whereas in Mar del Plata (cool-temperate = 37°S) these events are seasonal.…”

“…The effect of latitude on the population dynamics of penaeids has been studied by several authors (Bauer, 1992;Boschi, 1997;Gavio and Boschi, 2004;Castilho et al, 2007a, b;Costa et al, 2010). Furthermore, one of the main aims of reproductive ecology studies of benthic invertebrates is to evaluate the tendencies of geographical and temporal variations on the reproductive and juvenile recruitment activity (Bauer, 1992;Costa and Fransozo, 2004).…”

A test of large-scale reproductive migration in females of the amphidromous shrimp Macrobrachium acanthurus (Caridea : Palaemonidae) from south-eastern Brazil

“…For gonochoric (separate sexes) species such as M. acanthurus, sex allocation theory predicts equal sex ratios as parents should produce an equal number of male and female offspring because of frequency-dependent selection against the more common sex in the population (Fisher 1930). However, female or male skewed population-wise sex ratios have been reported before in other shrimps (Alon and Stancyk 1982;Bauer and Abdalla 2001;Fransozo et al 2004; Mejía-Ortíz and Alvarez 2010) and major causes for imbalances in sex ratio among marine invertebrates include sex-specific growth and/ or mortality rates (Wenner 1972), sex-dependant migration (Wenner 1972;Costa et al 2010), sex-dependant mating behaviours (Willson and Pianka 1963;Castilho et al 2008), and/or sampling error (Bolaños et al 2012). Sex-dependant migration does not appear to occur in the studied river.…”