Elevational Variation of Reproductive Traits in FivePardosa(Lycosidae) Species

Abstract

Differentiations in reproductive traits along climatic gradients can be substantial for a species to spread along a wide spatial range. We compared the reproductive effort allocated to first egg sacs of five species of the genus Pardosa: P. palustris (Linnaeus 1758), P. amentata (Clerck 1757), P. lugubris (Walckenaer 1802), P. hyperborea (Thorell 1872), and P. riparia (C. L. Koch 1833) along three elevation transects in central Norway. We tested whether population differences are consistent among the three transects, respectively along the elevational gradient. We assumed that the harsh environments of alpine areas would lead to adaptations in reproductive traits resulting in larger eggs but smaller clutches at higher elevations. The results show that female size and egg number were positively correlated among all species. However, no clear elevation-related trend was found. Other traits did not change consistently between species and along the elevational gradient. We assume that local microclimatic impacts on spider fitness are a crucial but poorly understood factor. Without further knowledge about adaptation and phenotypic plasticity in ectotherms, modeling of possible future reproduction biology might remain flawed.

Broad-scale rather than fine-scale environmental variation drives body size in a wandering predator (Araneae, Lycosidae)

“…However, Otto and Svensson (1982) found a decrease in body size in several Araneae species with elevation and assumed that it is advantageous to be of smaller size at higher elevations, because a smaller size makes it easier to seek shelter in open habitats if predators appear. In previous studies, we found body size in different Pardosa species to decrease, but also to increase with elevation in central Norway (Hein et al 2015), and there also seems to be a pronounced inter-annual variation in body size rather than a variation along the elevational gradient (Hein et al 2018). This corresponds with findings of Lee, Somers, and Chown (2011), who were not able to detect a linear trend in the size of the indigenous spider Myro kerguelensis (O.P.-CAMBRIDGE 1876) with elevational in a sub-antarctic environment.…”

“…The local abiotic factor topographic position, acting at the fine scale, is thus expected to show a higher explanatory power on body size than the regional abiotic factors of study region and elevation, which act at the broad scale. Consequently, this hypothesis was tested using a study design from fine-to broad-scale in order to gain insights into how extent local and regional factors shape body size in the highly mobile and locally abundant spider Pardosa palustris (e.g., Hauge and Refseth 1979;Hein et al 2014Hein et al , 2015.…”

Replicated latitudinal clines in reproductive traits of European and North American yellow dung flies

“…That low temperatures favour the evolution of larger eggs is now widely accepted (Armbruster et al 2001, Fischer et al 2003b) and may provide an explanation for the clines observed in many ectotherms. However, numerous examples exist in which ectotherms show either no cline in egg size with latitude/ altitude (Hein et al 2015, Kasimatis and Riginos 2016, Sniegula et al 2016, or a cline in which eggs get smaller at higher latitude or altitude (Blanckenhorn and Fairbairn 1995, Baur and Baur 1998, Johnston and Leggett 2002, Kokita 2003, indicating that the causes of clines are not universal.…”

Arañas (Arachnida: Araneae) Asociadas a Formaciones Vegetales en El Refugio De Vida Silvestre Pantanos De Villa, Lima, Perú

“…Las arañas lobo (Lycosidae) son consideradas modelos adecuados para diversos aspectos ecológicos, incluyendo la influencia de las condiciones ambientales. Además consideran que las arañas lobo se han convertido en la familia de arañas más estudiada hasta la fecha (Hein et al, 2015). Nuestros resultados coinciden con otros estudios, donde Lycosidae se caracteriza por presentar especies altamente activas sobre la superficie terrestre, y por ser una de las familias de arañas más abundante en los monitoreos de organismos de suelo en diferentes ecosistemas, presentando variaciones en sus patrones de abundancia espacial (Arana-Gamboa et al, 2014;Almada & Sarquis, 2017).…”