Doprinos poznavanju faune tulara (Insecta: Trichoptera) jezera Leqinat i obližnjih potoka na području Bjeshkët e Nemuna (Kosovo)

Adult caddisflies were collected with entomological nets and ultraviolet light traps during August and September 2018 in Leqinat Lake, Drelaj Lake and five adjacent streams in Bjeshkët e Nemuna in Kosovo. Within the current study we found three first records for the caddisfly fauna of Kosovo: Limnephilus flavospinosus, Limnephilus flavicornis and Oligotricha striata. The genus Oligotricha is reported for the first time from Kosovo. We also found few rare species which have been reported only from few localities in the Balkan Peninsula such as: Plectrocnemia mojkovacensis, Rhyacophila balcanica and Drusus tenellus.Odrasli tulari prikupljani su pomoću entomološke mrežice i UV svjetlosnih zamki tijekom kolovoza i rujna 2018. na jezerima Leqinat i Drelaj te pet obližnjih potoka, na području Bjeshkët e Nemuna na Kosovu. Tijekom istraživanja zabilježili smo tri prva nalaza za faunu tulara Kosova: Limnephilus flavospinosus, Limnephilus flavicornis i Oligotricha striata. Po prvi puta za Kosovo je zabilježen rod Oligotricha. Također smo našli neke rijetke vrste zabilježenih na samo nekoliko lokaliteta na Balkanu, npr.: Plectrocnemia mojkovacensis, Rhyacophila balcanica i Drusus tenellus

Columbia River plume fronts. II. Distribution, abundance, and feeding ecology of juvenile salmon

Well-defined fronts develop at the seaward edge of riverine plumes where suspended materials and planktonic organisms are concentrated by convergent water flows. Riverine plume fronts have been hypothesized to be favorable fish habitats because they can lead to localized prey aggregations. We examined the spatial distribution of juvenile Pacific salmonids Oncorhynchus spp. in and around plankton-rich frontal regions of the Columbia River plume to test the hypothesis that juvenile salmonids aggregate at riverine plume fronts to feed. Juvenile salmonids tended to be abundant in the frontal and plume regions compared to the more marine shelf waters, but this pattern differed among species and was not consistent across the 2 study years. Stomach fullness tended to be higher in the more marine shelf waters than either the front or plume areas, which does not support the hypothesis that salmonids consistently ingest more prey at frontal regions. Many prey organisms were disproportionately abundant at these fronts, but salmon stomach-content analysis did not reveal higher stomach contents at fronts or identify prey groups indicative of feeding in the frontal areas. Although our results indicate that the Columbia River plume influences the distributions of juvenile salmon, our observations do not support the hypothesis that juvenile salmonids congregate to feed at fronts at the leading edge of the Columbia River plume. The short persistence time of these fronts may prevent juvenile salmon from exploiting these food-rich, but ephemeral, features.Keywords: Feeding habits, Distribution, Juvenile salmon, Frontal regions, Columbia River plumeKeywords: Feeding habits, Distribution, Juvenile salmon, Frontal regions, Columbia River plum

Trophic specialisations in alternative heterochronic morphs

Polymorphisms are suspected of reducing competition among conspecifics in heterogeneous environments by allowing differential resource use. However the adaptive significance of alternative morphs has been poorly documented. The aim of this study is to determine food partitioning of two heterochronic morphs of the Alpine newt, Triturus alpestris, in mountain lakes. The morphs differ in the functional morphology of their feeding apparatus. Only paedomorphs are able to expel water during prey suction behind the mouth through gill slits. We observed a substantial trophic differentiation between morphs in all lakes. Paedomorphs preyed mainly on plankton, whereas metamorphs foraged on terrestrial invertebrates that fell upon the water surface. This resource partitioning may facilitate the coexistence of the alternative morphs in lakes devoid of vertebrate competitors. Food diversity may thus favour the evolutionary maintenance of facultative polymorphism in natural populations

Feeding specialization in heterochronic newts (Triturus alpestris, Amphibia, Caudata)

Polymorphisms are suspected to reduce competition among conspecifics in heterogeneous environments by allowing differential resource use. However, the adaptive significance of alternative morphs has been poorly documented. The aim of this study was to test this hypothesis by comparing diets of syntopic heterochronic morphs (paedomorphs and metamorphs) in the Alpine newt, Triturus alpestris in three European alpine lakes. Feeding performance was also tested in the laboratory. The two morphs differ in the functional morphology of their feeding apparatus. Only paedomorphs are able to expel water behind the mouth during prey suction through gill slits. We observed a substantial trophic differentiation between morphs consistently in all lakes. Paedomorphs primarily preyed on plankton whereas metamorphs foraged on terrestrial invertebrates that fell to the water surface. Laboratory observations were consistent with field patterns. In paedomorphs, prey capture success rate was better than in metamorphs when foraging on aquatic crustaceans, but was less successful when foraging on terrestrial invertebrates caught at the water surface. By reducing competition, resource partitioning contributes to the coexistence of the alternative morphs in lakes devoid of vertebrate competitors and predators. Food diversity is thus an important factor favoring the evolutionary maintenance of facultative paedomorphosis in natural populations

A new freshwater eutardigrade from Fiji and Vanuatu (Oceania), with remarks on the genus Dactylobiotus

A new freshwater eutardigrade, Dactylobiotus vulcanus sp. nov. is described from two volcanic crater lakes: Manaro Kesa (Lakua), Ambae Island (Republic of Vanuatu) and Tagimaucia, Taveuni Island (Republic of Fiji). The new species is most similar to Dactylobiotus dervizi and Dactylobiotus luci in the shape of the egg processes, smooth cuticle and the absence of dorso-lateral papillae, but it differs from them mainly by the absence of the oral cavity armature, the presence of eyes, the presence of minute areolation on eggs, and by several morphometric characters of adults and eggs. Additionally, we also discuss taxonomic positions of several dubious species within the genus, and provide the key to all known Dactylobiotus species

First Limnological Characterization of the Tropical Crater Lake Amparihibe in the Makira Protected Area, Madagascar. eco.mont (Journal on Protected Mountain Areas Research)|eco.mont Vol. 1 No. 1|

The newly established Makira Protected Area and its environs in Northeast Madagascar host roughly 50% of the entire Malagasy floral biodiversity, but very little was known about the two freshwater lakes found within the park. Lake Amparihibe was explored for the first time in November 2007. According to preliminary 40Ar/39Ar dating, the volcanic crater formed as far back as 25.3 million years ago, but no information is available about when the crater started to fill with water. The protected crater lake has a maximum depth of 28 m and was anoxic beyond a depth of 15 m. During the single sampling occasion, steep gradients in temperature, oxygen, conductivity and pH revealed a stable stratification. Several phyto- and zooplankton taxa showed distinct depth-specific abundance maxima along the steep physico-chemical gradients. The majority of plankton organisms have a cosmopolitan (tropical and temperate) distribution, however more taxonomic research is necessary before definitive conclusions can be drawn. Exposure of a multi-mesh gill net together with visual inspection by snorkeling yielded no presence of fish. Despite the full protection status of the park, illegal introduction of alien fish species seems a realistic threat to this pristine Malagasy lake