Seasonal variation in reproductive traits of the oriental shrimp Palaemon macrodactylus (Crustacea: Caridea: Palaemonidae) in a non-native population

Abstract

The magnitude of variations in reproductive traits of Palaemon macrodactylus females throughout a breeding season was studied in a non-native population at Mar del Plata harbor, Argentina. Fecundity, egg size, reproductive output, weight and elemental composition of eggs, and larvae were analyzed in females collected at the beginning, in the mid point, and near the end of a reproductive season and designated as early, middle season, and late females. The highest reproductive output was observed in early females, while the highest fecundity and egg volume occurred in middle season females. Eggs and larvae showed larger body mass in early than in late females. Embryos from early females contained and consumed more carbon during development than embryos from late females, and they also used part of the available nitrogen. Differences in reproduction were observed among the three groups of females. On the one hand, late females matured early but had a poor first reproduction, with few embryos and high egg loss; however, they had longer reproductive life and an enhanced reproductive output in the following season when they became early females. On the other hand, females collected at the midpoint in the reproductive season matured later and had the highest fecundity and egg volume. In addition, larvae with different characteristics resulted from each type of female and were presumably well adapted to the conditions prevailing at the moment they hatched. The extended reproductive period and the diversity of embryos and larvae produced may favor the invading ability of the species.

Effects of temperature and salinity on larval survival and development in the invasive shrimp Palaemon macrodactylus (Caridea: Palaemonidae) along the reproductive season

“…Even when the experiments of Little (1969) and those reported in this study are not directly comparable, both reflect the high larval variability of this species and suggest that the conditions faced by females during ovarian development and/or by the embryos could be of paramount importance for larval performance. These results the perspective that P. macrodactylus is a species with high physiological and developmental plasticity as was previously suggested (Vázquez et al, 2013b) and as has been demonstrated in other palaemonid shrimps (González-Ortegón et al, 2013). Carapace length of juveniles was not affected by the larval type but depended on the rearing salinity.…”

“…Most adult crustaceans tolerate ranges of temperature and salinity wider than larval stages (Charmantier, 1998;Sastry, 1983). In the oriental shrimp, females were able to survive and develop their ovaries in salinities ≥5 psu, but embryonic development was possible in the same salinity range than larvae (12-34 psu) (Vázquez et al, 2013b). In addition, larvae hatched at the beginning, in the midpoint and at the end of the reproductive season have different patterns of use of metabolizable energy, presumably as an adaptation to the conditions prevailing at hatching (Vázquez et al, 2013b).…”

“…A third group of small females became evident near the end of the season (February-March); they grew and matured after large females died; this new group included all reproductive females at this moment. Females from each reproductive group produce eggs and larvae that differ in size and energy content (Vázquez et al, 2013b).…”

Behaviour in a novel environment provides clues to the success of an invasive species

“…Its dispersion due the human activity began in the 1950s and currently it has an almost worldwide distribution (Ashelby et al, 2013). Studies carried out on P. macrodactylus ' life history, reproduction and physiological capacity (Béguer et al, 2011; González‐Ortegón et al, 2006, 2013; Lejeusne et al, 2014; Omori & Chida, 1988a, 1988b; Vázquez et al, 2012; Vázquez, Ituarte et al, 2013, Vázquez, Bas et al, 2013) have shown that this species has the potential to live and reproduce successfully in a broad range of conditions, which is certainly important to their success as invader. However, we are far from understanding how these potentially important characteristics can come to operate from the introduction of a few individuals into a new environment.…”

Temperature-mediated developmental plasticity in winter and summer larvae of Palaemon serratus

“…The largest larvae correspond to the most difficult environmental conditions, such as the beginning of the season (González-Ortegón et al, 2018;Paschke, 1998;Paschke et al, 2004;Urzúa and Anger, 2013). Thus, decapods living in seasonally variable environments and reproducing several times during the year show a seasonal pattern in the "fertility x offspring size trade-off" (Bas et al, 2007;Boddeke, 1982;Vázquez et al, 2013). The developmental pathways of the larvae of these species should be seasonally different, linked to the difference in larval size between the seasons.…”