Temperature-induced oviposition in the brachyuran crab Cancer setosus along a latitudinal cline: Aquaria experiments and analysis of field-data

Abstract

Ovigerous females of Cancer setosus are present year-round throughout most of its wide range along the Peruvian/Chilean Pacific coast (2°S-46°S). However, their number of egg-masses produced per year remains speculative and as such has neither been considered in latitudinal comparisons of reproduction, nor for its fisheries management. In order to reveal the effect of temperature on egg-mass production and eggdevelopment, female C. setosus were held in through-flow aquaria under natural seasonal temperature conditions (16-23°C) in Antofagasta (23°S), Northern Chile (05/2005-03/2006; 10 months), and at three constant temperatures (12, 16, 19°C) in Puerto Montt (41°S), Central Southern Chile (09/2006-02/2007; 5 months). Female crabs uniformly produced up to 3 viable egg-masses within 4 1/2 months in Antofagasta and in Puerto Montt (at 19°C). The second egg-mass was observed 62.5 days (± 7.6; N = 7) after the oviposition of the first clutch and a third egg-mass followed 73.5 days (± 12.5; N = 11) later in Antofagasta (at 16-23°C). Comparably, a second oviposition took place 64.4 days (± 9.8, N = 5) after the first clutch and a third, 67.0 days (± 2.8, N = 2), thereafter, at 19°C in Puerto Montt. At the two lower temperatures (16 and 12°C) in Puerto Montt a second egg-mass was extruded after 82.8 days (± 28.9; N = 4) and 137 days (N = 1), respectively. The duration of eggdevelopment from oviposition until larval hatching decreased from 65 days at 12.5°C to 22.7 days at the observed upper temperature threshold of 22°C. Based on the derived relationship between temperature and the duration of egg-development (y = 239.3175e − 0.107x ; N = 21, r 2 = 0.83) and data on monthly percentages of ovigerous females from field studies, the annual number of egg-masses of C. setosus was calculated. This analysis revealed an annual output of about one egg-mass close to the species northern and southern distributional limits in Casma (9°S) and Ancud (43°S), respectively, while at Coquimbo (29°S) about two and in Concepción (36°S) more than 3 egg-masses are produced per year.

Temperature effects on zoeal morphometric traits and intraspecific variability in the hairy crab Cancer setosus across latitude

“…Quintana and Saelzer (1986) showed that zoeal development of C. setosus larvae of a population from Coliumo Bay (Concepción, central Chile) takes about 60 days under natural temperature conditions (13.5-14.6°C), while larvae from the Antofagasta region have a 1.5 times exceeded zoeal development at 16°C and show higher survival rates (Weiss et al 2009b), and larvae from Concepcion are capable to develop through all zoeal instars at lower temperatures. These Wndings indicate a better cold adaptation of larvae originating from a southern population (see also Fischer and Thatje 2008;Fischer et al 2009a) and from an evolutionary point of view could be considered ancestral to further abbreviated larval developments (Strathmann 1978), which is favourable for larvae from colder regions.…”

“…A unique physiological plasticity to respond to latitudinal and seasonal changes in temperature has been observed in reproductive traits of C. setosus. Among the most conspicuous characteristics is a synchronisation of a single egg batch release with seasonality at the species southernmost distribution boundary in central southern Chile (Puerto Montt, 41°44Ј S), contrasted by multiple annual ovipositions in northern Chile (Antofagasta, 23°45Ј S) (Fischer and Thatje 2008). In addition, a correlation of changes in egg energy contents and temperature was observed along latitude as well as in subsequent ovipositions in the same female (Fischer and Thatje 2008;Fischer et al 2009a).…”

“…Among the most conspicuous characteristics is a synchronisation of a single egg batch release with seasonality at the species southernmost distribution boundary in central southern Chile (Puerto Montt, 41°44Ј S), contrasted by multiple annual ovipositions in northern Chile (Antofagasta, 23°45Ј S) (Fischer and Thatje 2008). In addition, a correlation of changes in egg energy contents and temperature was observed along latitude as well as in subsequent ovipositions in the same female (Fischer and Thatje 2008;Fischer et al 2009a). These Wndings are consistent with the concept of a latitudinal gradient in energy provisioning into oVspring of a broad variety of marine invertebrates (for review see Thatje et al 2005).…”

Changes in biomass and elemental composition during early ontogeny of the Antarctic isopod crustacean Ceratoserolis trilobitoides

“…include a reduction in fecundity, increase in egg size and energy per offspring with increasing latitude (Clarke et al 1985;Shilling and Bosch 1994;Fischer and Thatje 2008). Such reproductive patterns seem evident at least in decapod crustaceans, prosobranch molluscs, and echinoderms (Thorson 1936(Thorson , 1950Clarke 1979;Clarke et al 1985;Pearse et al 1991;Thatje et al 2005).…”

“…Such reproductive patterns seem evident at least in decapod crustaceans, prosobranch molluscs, and echinoderms (Thorson 1936(Thorson , 1950Clarke 1979;Clarke et al 1985;Pearse et al 1991;Thatje et al 2005). However, the mechanisms driving latitudinal patterns in reproduction are far from being fully understood although often related to adaptations to decreasing temperature and more pronounced seasonality towards higher latitudes (Clarke 2003;Pearse and Lockhart 2004;Thatje et al 2005;Fischer and Thatje 2008).…”