Early egg traits in Cancer setosus (Decapoda, Brachyura): effects of temperature and female size

Abstract

Previous study on Cancer setosus Molina, 1782 showed that latitudinal changes in temperature control the number of annual egg masses. This study focused on the effects of preoviposition temperature and female size on egg traits in C. setosus from northern (Antofagasta, 23°S) and central-southern (Puerto Montt, 41°S) Chile. Blastula eggs produced in nature ranged in dry mass (DM) from 9.1 to 15.1 µg, in carbon (C) from 4.8 to 8.4 µg, in nitrogen (N) from 1.0 to 1.6 µg, in C:N ratio between 4.7 and 5.4, and in volume (V) between 152 and 276 mm 3 × 10 -4 per female. Blastula eggs from females caught early in the reproductive season in Puerto Montt (September 2006) were significantly higher in DM, C, N, and V than those of females caught 2 mo later, reflecting a seasonal increase in water temperature. In Puerto Montt 'early' and 'late' season blastula eggs were higher in DM, C, N, and V than eggs from Antofagasta by about 32 and 20%, respectively. Subsequent egg masses produced in captivity in Puerto Montt followed this pattern of smaller eggs with lower DM, C, and N content at higher pre-oviposition temperatures. In Antofagasta no significant difference in DM, C, N, and V between eggs produced in nature and subsequent eggs produced in captivity was found and all egg traits were significantly positively affected by maternal size. Reproductive plasticity in C. setosus helps to explain the species wide latitudinal distribution range.KEY WORDS: Crustacea · Cancridae · Chile · Latitudinal cline · Reproductive plasticity 377: 193-202, 2009 Within the Crustacea, seasonal (Boddeke 1982, Amsler & George 1984, Sheader 1996, Paschke 1998), inter-annual (Kattner et al. 1994) and latitudinal (Crisp 1959, Clarke et al. 1991, Wehrtmann & Kattner 1998, Lardies & Castilla 2001, Lardies & Wehrtmann 2001, Brante et al. 2003 intraspecific differences in egg traits have been reported. Furthermore, in Crustacea with consecutive ovipositions, egg quality may vary with spawning order, a feature of considerable importance in shrimp aquaculture (e.g. Arcos et al. 2003, Racotta et al. 2003. Resale or republication not permitted without written consent of the publisherMar Ecol Prog SerHowever, unless common environment experiments are conducted, it remains speculative if latitudinal differences in reproductive traits are based on genetic differences or represent adaptive phenotypic responses to environmental heterogeneity (e.g. temperature) (see Kokita 2003).In the brachyuran crab Cancer setosus Molina, 1782, which is distributed over more than 40°of latitude along the South American Pacific coast (2°S, 079°W to 46°S, 075°W; Fig. 1) (Rathbun 1930), fecundity per egg mass, egg dry mass, and egg volume increases with increasing latitude (Brante et al. 2003(Brante et al. , 2004. At its southern range C. setosus incubates one annual egg mass throughout the austral winter until the time of larvae hatching in spring. In central-and northern Chile, reproduction is not restricted to a certain season leading to an annual output of ab...

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

“…Those energy saving traits of producing larger eggs and early larval instars at higher latitudes (colder temperatures) once more support the controversially discussed but often supported "Thorson's rule" (Mileikovsky 1971;Clarke 1993;Thatje and Bacardit 2000) that appears to be particularly useful for the evaluation of energetic trait-oVs in decapods . Fischer et al (2009b) found more energy rich fatty acids in the southern than in the northern population eggs, independent of the incubation temperature. This might indicate a genetic adaptation to colder temperatures and might be a selection in the direction of non-feeding larvae and hence towards lecithotrophic development, which is indicating the beginning of an abbreviated development (Thatje et al 2005).…”

“…Puerto Montt is located close to the southern limit of this species. In Antofagasta Bay, SST is signiWcantly higher than in the surrounding Humboldt Current upwelling system (+2-3°C) due to the bay's particular oceanographic conditions (Piñones et al 2007), and thus SST is comparable to the temperature encountered by C. setosus at its northern distributional limit oV Ecuador (Fischer et al 2009b). Two females (IDs A, B) (inXuence of temperature encountered during larval development) in Antofagasta were maintained individually in Xow-through seawater aquaria (12 l) at ambient temperature »16.0°C, while four females (IDs C, D, E, and F) (inXuence of temperature encountered during embryonic development on larval morphology) were held in 3,200 l Xow-through aquaria (·12 ind./basin) under natural seasonal temperature conditions (up to 10 months; 16-23°C) in Antofagasta.…”

“…This has been shown for the Dungeness crab, Cancer magister (Shirley et al 1987), the spider crab, Hyas araneus (Kunisch and Anger 1984) as well as for caridean shrimps like Nauticaris magellanica (Wehrtmann and Kattner 1998), Betaeus emarginatus (Wehrtmann and López 2003), and Pandalus borealis (Brillon et al 2005) in laboratory cultures, and for Nauticaris magellanica from the Weld (Thatje and Bacardit 2000). In C. setosus eggs from a southern Chilean population were larger containing higher lipid content, resulting in bigger larvae than eggs from northern Chile (Fischer et al 2009b). Egg development in the southern population is primarily based on the metabolism of energy rich lipids, which Wnally enhances the energetic Wtness of the hatching larvae, and which has been discussed as an adaptive response to colder temperatures and prolonged egg and larval developmental time (Fischer et al 2009b).…”

“…In C. setosus eggs from a southern Chilean population were larger containing higher lipid content, resulting in bigger larvae than eggs from northern Chile (Fischer et al 2009b). Egg development in the southern population is primarily based on the metabolism of energy rich lipids, which Wnally enhances the energetic Wtness of the hatching larvae, and which has been discussed as an adaptive response to colder temperatures and prolonged egg and larval developmental time (Fischer et al 2009b).…”

Energetic changes throughout lecithotrophic larval development in the deep-sea lithodid crab Paralomis spinosissima from the Southern Ocean

“…Larval lecithotrophy in lithodids is likely the result of their global radiation through the deep sea (Hall and Thatje, 2009b) and different levels in energy allocation into offspring may represent a response to changes in local ambient temperature (for discussion see also Fischer et al, 2009). Decapod crustaceans are among the best-studied taxa that indicate to follow a latitudinal cline in eggs size (as a measure of energy content) with temperature across latitude (Clarke, 1987;Lovrich et al, 2005;Wehrtmann and Kattner, 1998;Thatje et al, 2005b).…”