Comparative study of mathematical models for the relationship between water temperature and brood development time of Gammarus fossarum and G. roeseli (Crustacea: Amphipoda)

Abstract

1. The relationship between water temperature (T°C) and brood development time (d days for embryonic development time plus •post-hatch time') was investigated experimentally using animals from four populations of Gammarus fossarum (populations 1-4) and two populations of C. roeseli (populations 5 and 6) in Austrian streams.2. Eleven mathematica] models were examined as suitable functions to describe the relationship between d and T. The models were compared with respect to their goodness-of-fit and suitability for further quantitative, statistical analyses of intra-and interspecific differences between natural populations of G. fossarum and G. roeseli.3. Statistical analyses were performed with logarithmically transformed values of d. in order to provide homogeneous variances between the different constant temperatures used. The following three-parameler model was found to be the most suitable for the data: d=a exp [-^1 In T~CiT\.

How to be an invasive gammarid (Amphipoda: Gammaroidea)–comparison of life history traits

“…The higher productivity of a species is a result of fecundity, embryological development time, time of gaining the ability to reproduce, mortality of juveniles etc. It enables one species to outnumber another species with lower potential (Poeckl & Humpesch, 1990;Poeckl & Timischl, 1990;Costello, 1993;Kley & Maier, 2003;Poeckl, 1993), such as is suggested in our analyses. Invasive species such as P. robustoides, D. villosus and D. haemobaphes have very high productive potential, which is expressed by very high fecundity, early maturity, and repeated reproduction (three generations) each year.…”

Salinity-related distribution of alien amphipods in rivers provides refugia for native species

“…However, in some cases with unfavourable conditions, the invaders may not be able to outnumber the natives. In colder rivers the population growth of alien Gammarus roeselii was slower due to obstructions in embryonic development, and the species was eventually replaced by the native Gammarus fossarum, which is better adapted to such conditions (Poeckl and Humpesch 1990;Poeckl and Timischl 1990;Poeckl 1993). In warmer rivers the situation was reverse.…”

“…It does not thrive in springs and very small streams. The reason for that are higher thermal demands of the species (Karaman and Pinkster 1977;Poeckl and Humpesch 1990;Poeckl and Timischl 1990;Poeckl 1993;Wijnhoven et al 2003;Bollache et al 2004). The tendency of other observed exotic species to thrive only in large rivers can be explained by their possible euryhalinity and euryoeciousness, features that are advantageous in polluted and anthropogenically altered environments.…”

Environmental factors modulating the extent of impact in coastal invasions: The case of a widespread invasive caprellid (Crustacea: Amphipoda) in the Iberian Peninsula

“…In the case of freshwater amphipods, Kestrup and Ricciardi (2009) showed that conductivity mediates the rate and direction of interspecific predation between the invasive amphipod Echinogammarus ischnus and the native amphipod Gammarus fasciatus in the Great Lakes basin. In addition to salinity, temperature has been observed as another important factor driving biotic interactions among native and invasive freshwater amphipods (Poeckl and Timischl, 1990). Taking into account that salinity was highly positively correlated to temperature along the Iberian Peninsula, we may assume that a combination of relatively high temperature and salinity could favor the competitive Table 3 Model averaged coefficients (b) of explanatory variables present in the significant models for: (a) C. scaura presence/absence, (b) C. scaura abundance, (c) C. equilibra presence/absence, (d) C. equilibra abundance.…”