Life History of a Population of Protonemura intricata (Ris, 1902) (Insecta, Plecoptera) in a Constant Temperature Stream in Central Europe

Abstract

The nymphal biology (life cycle, secondary production and feeding) of a population of Protonemura intricata was studied in a calcareous stream with almost constant temperature (7-8 °C) through the year at Prosiek valley (Chočské Vrchy Mts., West Carpathians, Slovakia). The results were compared with those previously known for this species in other areas. According to our data, the species has a complicated life cycle consisting of two cohorts with different duration (probably a cohort splitting). This life cycle seems to be uncommon among the Plecoptera, which usually has simple univoltine or semivoltine life cycles, and could be probably attributed to the constant temperature regime similar to that of tropical environments. One factor, the photoperiod length, was positively correlated with monthly growth rates. The nymphal growth varied throughout the year, but the highest growth was in late spring and summer, and the lowest was in winter. The annual secondary production was very high (909.4 mg · m -2 ) despite not being the most frequent taxon in the stream. The highest monthly production values were observed in the autumnal-winter period (November-December) due to massive hatching of nymphs. The lowest production values were observed in late summer and early autumn. Analyses of gut contents showed that this species behaves mainly as gatherer-collector, but also as shredder and, occasionally, as scraper. Changes in the gut content composition were detected in relation to the size. Comparing our results with those of the literature, it can be inferred that different populations of P. intricata can show notable differences in their life history when inhabiting places with different thermal conditions. IntroductionOne of the most important aspects for understanding freshwater ecosystems is the biology of the species that live in them. In this context, the study of the life history of single species is essential in order to achieve a full knowledge of the ecosystem itself and the relations within it. Many studies have tried to reach this goal through generalizations taken from the study of a reduced number of species, assuming that the rest of the members of their genus or family behave in the same manner. As pointed out by several authors (ZWICK, 1981;STEWART and STARK, 1993), this is neither a good approximation nor an appropriate * Corresponding author 58 Z. KOZÁČEKOVÁ et al.

Life history and secondary production of Electrogena ujhelyii (Ephemeroptera: Heptageniidae) in a small forest stream in West Carpathians

“…Many studies focusing on the life histories of mayflies (Landa 1969;Sowa 1975;Clifford 1982;Elliott et al 1988;Studemann et al 1992;Bauernfeind & Humpesch 2001;López-Rodríguez et al 2008) and comparative investigations on already described life histories are necessary from the viewpoint of the developmental flexibility in various geographical regions and environmental conditions. In this context, the study of the life history of the single species is essential in order to achieve a full knowledge of the ecosystem itself and the relations within it (Kozáčeková et al 2009). The information about life cycle of E. ujhelyii are very limited, Sowa (1981) suggested one generation per year, Řezníčková et al (2010) mentioned univoltine winter life cycle, but without detailed data.…”

Trophic ecology of Plecoptera (Insecta): a review

“…Accidental ingestion of animal remains by non-predator species is widespread among stoneflies (e.g. Brinck 1949;Cummins 1973;Díaz Villanueva & Albariño 1999;Albariño 2001;Kozáĉeková et al 2009). Some authors suggest that the ingestion of such animal matter by nonpredatory insects is a way to adapt to a nutrient-deficient diet (Price et al 2011).…”

“…In fact, it is commonplace for some to swallow sand grains and other mineral particles when feeding (e.g . Brinck 1949;Brittain 1973;Derka et al 2004;Zwick & Hohmann 2005;Kozáĉeková et al 2009;Silveri et al 2009;. Albeit accidental, some authors point out that mineral material could act as a gridding crop in some periphyton and detrital feeders (Cummins 1973).…”

The unusual life history of a southern Iberian Peninsula population of Torleya major (Ephemeroptera: Ephemerellidae)

“…Cohort splitting, namely the variability in life cycle duration within populations, is a relatively uncommon life strategy in aquatic insects. It has been reported in some species of several orders, such as Ephemeroptera, Odonata, Plecoptera, Trichoptera and Diptera, (e.g., Butler, 1984; Alba‐Tercedor, 1990a; Danks, 1992; Kozáčeková et al , 2008; Lieske & Zwick, 2008). Within mayflies it has been mainly reported in species of the family Ephemeridae (particularly in the genera Hexagenia and Ephemera ), that are semivoltine (Butler, 1984; Alba‐Tercedor, 1990a; Danks, 1992); although some Baetidae and Caenidae species may also exhibit this phenomena (Bengtsson, 1988; Taylor & Kennedy, 2003).…”

“…It has been reported in some species of several orders, such as Ephemeroptera, Odonata, Plecoptera, Trichoptera and Diptera, (e.g., Butler, 1984;Alba-Tercedor, 1990a;Danks, Correspondence: M. J. López-Rodríguez, Departamento de Biología Animal, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain. Fax: +34 958243238; email: manujlr@ ugr.es 1992; Kozáčeková et al, 2008;Lieske & Zwick, 2008). Within mayflies it has been mainly reported in species of the family Ephemeridae (particularly in the genera Hexagenia and Ephemera), that are semivoltine (Butler, 1984;Alba-Tercedor, 1990a;Danks, 1992); although some Baetidae and Caenidae species may also exhibit this phenomena (Bengtsson, 1988;Taylor & Kennedy, 2003).…”