Temperature effects on life history traits of two sympatric branchiopods from an ephemeral wetland

Abstract

Temperature effects on organisms are of multiple scientific interests, such as for their life history performance and for the study of evolutionary strategies. We have cultured two sympatric branchiopod species from an ephemeral pond in northern Taiwan, Branchinella kugenumaensis and Eulimnadia braueriana, and compared their hatching rate, maturation time, sex ratio, growth of body length, survivorship, clutch size, net reproductive rate R0, generation time TG, and intrinsic rate of natural increase r in relation to temperature (15, 20, 25 and 30°C). We found that E. braueriana had a significantly higher temperature-dependent fecundity and intrinsic population growth pattern (R0 and r). In contrast, B. kugenumaensis reproduced much slower than E. braueriana with much lower R0 (90–100 folds less) and r (about 10 folds less) at 15, 20 and 25°C and with a double as long TG at 20 and 25°C. In addition, E. braueriana increased its chance of hermaphroditic sexual reproductive mode at higher temperature because of a significantly delayed maturation of males from hermaphrodites. In contrast, B. kugenumaensis showed no significant change in reproductive mode with temperature. This is the first study indicating a significant differentiation in life history parameters of two sympatric branchiopods mediated by temperature.

Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply

“…In a world of climate change, phytoplankton communities face a large variety of challenges due to manifold changes. Rising temperatures, e.g., directly influence many physical and physiological processes (Hatt, 1983;Connelly et al, 2009;Gross-Wittke et al, 2010;Warren et al, 2012;Pachepsky et al, 2014;Havens et al, 2015;Huang and Chou, 2017). Besides these direct temperature effects on organisms, increasing temperature leads to a phenological shift, i.e., spring starts earlier and summer lasts longer (Stine et al, 2009).…”

Ecological stasis in Spinicaudata (Crustacea, Branchiopoda)? Early Cretaceous clam shrimp of the Yixian Formation of north‐east China occupied a broader realized ecological niche than extant members of the group

“…Belk & Belk () reared Caenestheriella setosa and report an optimum of 25°C for number of eggs hatching. Accelerated growth at the same optimum in comparison to lower temperatures has also been identified in Eulimnadia braueriana (Huang & Chou ). In addition, the growth of C. gynecia was found to be distinctly slower in autumn populations (lower temperatures) than in their summer equivalents, resulting in more closely‐spaced growth lines.…”

“…The main ecological factors influencing the development of clam shrimp are temperature, population density, salinity, turbidity and the relative permanency of sites (Mattox ; Horne ; Timms & Richter ; Stoch et al . ; Huang & Chou ).…”

“…). A strong temperature effect on clam‐shrimp size has been identified in extant spinicaudatans (Huang & Chou ) but the proposed oxygen effect has not been tested yet. Environmental conditions might also have influenced hatching propensity of E. middendorfii (thus indirectly population size).…”

“…There are important temperature effects that influence hatching, the size of nauplii, and the post‐larval development (Mattox & Velardo ; Belk & Belk ; Eriksen & Brown ; Brendonck ; Huang & Chou ). Hatching takes place after a species‐specific temperature has been reached, for example 13°C for wet and 17°C for dried eggs of Cyzicus gynecia .…”