Notes on the genus Agnetina (= Phasganophora) (Plecoptera: Perlidae)

Genus Agnetina Klapálek, 1907 is removed from synonymy with Dinocras Klapálek, 1907 and synonymy between Agnetina and Phasganophora Klapálek, 1914 is established. A list of presently recognised nominal species of Agnetina is provided. For all west palaearctic species, i.e., A. elegantula (Klapálek), A. senilis Klapálek, A. werneri (Kempny), comb, n., lectotypes are designated. Distinctive characters of these three species are described, external male genitalia and eggs are illustrated. Asian A. brevipennis (Navás), comb, n., is briefly compared. A. dubia nom. n. is proposed to replace A. brevipennis Klapálek, 1921 (not Navás, 1912), a doubtful Asian species. A. pedata (Koponen, 1949) and A. undaata (Klapálek, 1921) are considered possible synonyms of A. senilis. which is for the first time recorded from Central Asia (Baikal area).     

A New Synonymy in the Genus Pteronarcys (Plecoptera: Pteronarcyidae)

Pteronarcys macra Ra, Baik et Cho, 1991 from South Korea is a new junior synonym of P. sachalina Klapálek, 1908. P. sachalina is frequently sympatric with P. reticulata Burmeister, 1839, and new characters to distinguish the larvae of both species are presented.     

Notes on plecoptera (17) Isoperla pusilla (Klapálek, 1923), comb.n., the valid name of Isoperla minima lilies, 1963

A lectotype is designated for Chloroperla pusilla Klapálek, 1923, which is transferred to genus Isoperla. Isoperla minima lilies, 1963, is its junior synonym and becomes invalid. The species is known from the Romanian Carpathians and Slovenia.     

Notes on Plecoptera (19) Isoperla lugens (Klapalek, 1923), replaces I. alpicola Brinck, 1949

A male lectotype and several paralectotypes of Chloroperla lugens Klapálek, 1923 are designated. The species is transferred to genus Isoperla and is the valid name for Isoperla alpicola Brinck, 1949.     

Additional data concerning the revision of the genus <Emphasis Type="Italic">Agnetina</Emphasis> Klapálek (Plecoptera,Perlidae) of the Eastern Palaearctic

In addition to the recent revision of the genus Agnetina Klapálek (Sivec et al., 2005), a list of the examined material (males, females, and larvae), including the type material is given. The main diagnostic characters for each species are also mentioned.     

A new species of Ilyocryptus (Crustacea: Anomopoda) from the River Paraná basin,Argentina

A new species of Ilyocryptus Sars from several localities in River Paraná basin, is described and figured. By the presence of a lateral process on the valves I. paranaensis n.sp. resembles I. cornutus Mordukhai-Boltovskoi & Chircova, but it shows several morphological differences in the shape and the armature of the postabdomen and in the antennal formula.     

Drumming signals within the family Taeniopterygidae (Plecoptera)

Drumming signals of the 11 species of Palaearctic Taeniopterygidae are described for the first time based on the study of populations from nine different European countries from Spain to Russia. In this way, a contribution is made to our knowledge of the constancy respectively the divergence of signals typical for the species distributed over a very wide area. Communication patterns of the family under varying temperatures were analysed. The dependence on temperature indicates that the adults of this family are cold stenothermic insects. Within the genus Brachyptera (Newport, 1851), the call signal of males is significantly different from their response signal (duration and drumming frequency). The marked modulation of the drumming frequency, e.g., of B. risi (Morton, 1896) and B. seticornis (Klapálek, 1902) is reached by a modulation of the amplitude of abdominal movements. Based on the study of the drumming signals, Taeniopteryx auberti (Kis and Sowa, 1964) is proposed as a subspecies of T. hubaulti (Aubert, 1946). Actual intensity of the drumming signals of T. auberti was measured. Taeniopteryx hubaulti is recorded for the first time outside the Alps.     

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

Abstract The nymphal biology of a population of Torleya major (Klapálek) in southern Iberian Peninsula was studied. An atypical life cycle pattern is described, with eggs hatching in August producing a fast‐developing cohort with adults emerging in autumn and a second slow‐developing cohort with adults emerging in spring of the following year. Nymphal growth occurred primarily in summer–autumn (in the first cohort) and in spring (in the second). The origin of such a life history is discussed. Nymphs were collector‐gatherers, consuming mainly detritus. Although ontogenetic shifts on the use of trophic resources were detected, similar food was utilized during the months when both cohorts cohabited, eliminating the possibility that the rapid growth of the first cohort could be related to the utilization of different food resources.     

Molecular systematics and biogeography of the western Mediterranean stonefly genus Tyrrhenoleuctra (Insecta, Plecoptera)

The stonefly genus Tyrrhenoleuctra includes species living in western Mediterranean temporary freshwater streams, sometimes also at sea level, a very unusual habitat for most Plecoptera. Traditional morphological approaches proved unsuccessful in drawing both taxonomic and phylogenetic patterns, thus hampering discussion of biogeographical patterns for this interesting group. We aimed at: (a) assessing the taxonomic status of populations of Tyrrhenoleuctra covering the geographic range of the genus; (b) studying the phylogenetic relationships among the recognized species; and (c) describing biogeographic patterns. We used phylogenetic analyses to infer the phylogenetic history of this group of stoneflies based on a combined data set of 1666 bp including fragments of the 12S ribosomal (12S) and cytochrome oxidase I (CO‐I) mtDNA genes, with maximum likelihood and Bayesian methods. Two main clades have been identified: a Sardo‐Corsican one, including Tyrrhenoleuctra zavattarii, and an Ibero‐Maghrebian one including four lineages of unkown taxonomic rank from the Balearic Islands (Maiorca), from northern Africa (Ceuta) and southernmost Spain (Algeciras), and a complex preliminarily referred herein to T. minuta (Klapálek, 1901), which includes two lineages, one from Cordoba, and one from Sierra de Grazalema (El Cerro) and Portugal (Tellhares) respectively. Dating the nodes by fixing the split of the Ibero‐Maghrebian clade from the Sardo‐Corsican one at 29 million years ago (Mya), yielded dates referring to the major geological events in the Mediterranean basin. Estimated molecular evolutionary rates ranged from 0.02–0.09% per million years (my) in the T. zavattarii lineages, to 0.2–0.7% per MY in the Ibero‐Maghrebian clade. The phylogenetic pattern emerged from the present study is congruent with the known paleo‐history of the western Mediterranean basin, with the divergence of the two main Tyrrhenoleuctra lineages corresponding to the split of the Sardo‐Corsican microplate from the Iberian block. Vicariance events have characterized the history of this stonefly group along its entire biogeographical history. Surprisingly low evolutionary rates, previously supposed by Fochetti (1991, 1994) and Fochetti et al. (2004) based on nuclear markers (allozymes), have been herein found also in mitochondrial markers.     

Distribution of non‐native suckermouth armoured catfish Pterygoplichthys ambrosettii in the upper Paraná River basin,Brazil

This study describes the invasion of the upper Paraná River basin by Pterygoplichthys ambrosettii based on a literature review and field samples. Pterygoplichthys ambrosettii has been reported in 42 localities throughout the upper Paraná River basin, including the Tietê, Paranapanema, Paraná, Grande and Aguapeí rivers. The ascent of P. ambrosettii after the inundation of the Sete Quedas Falls on the Paraná River and the release of individuals by aquarium hobbyists were the primary drivers of this invasion.     

Distribution Patterns,Species Assemblages and Habitat Selection of the Stoneflies (Plecoptera) from Two Mediterranean River Basins in Southern Spain

The stonefly distribution and its relationship with habitat changes, based on stream physico chemical features, were investigated in two Mediterranean river basins (Guadaira and Guadalete, S Spain). Plecopteran nymph distribution varied along an elevation gradient. Both stonefly species richness and species diversity increased with altitude. Stoneflies were able to tolerate a wide range of environmental conditions but were absent from low altitude sites, temporary streams with high salinity values and high water temperature. A total of 13 stonefly species were found in the study area, from which Tyrrhenoleuctra minuta (Klapálek ) and Protonemura sp. were dominant. The most widespread species were Nemoura lacustris and Capnioneura mitis. Three distinct species assemblages were observed according to their distribution patterns, but with similar environmental preferences. Capnioneura petitpierreae and T. minuta showed preferences to low altitude sites, whereas C. mitis and N. lacustris were found throughout all sites. T. minuta and N. lacustris inhabited permanent and temporary sites, while the same species and C. mitis also were found in semipermanent streams. Temporally, most stoneflies were caught during winter (85.9%), especially at the low altitude sites.     

First record of non‐native hybrid catfish Pseudoplatystoma reticulatum × Leiarius marmoratus in the Upper Paraná River basin,Brazil

The aim of this study is to report the presence of a three non‐native hybrid long‐whiskered catfishes (family Pimelodidae) in the Upper Paraná River basin, Brazil. Genetic analyses demonstrated that the three presumptive hybrids were a result of the crossbreeding of Pseudoplatystoma reticulatum (central Amazonas River basin and Lower Paraná River) and Leiarius marmoratus (Amazonas, Essequibo and Orinoco rivers), producing a hybrid commonly known in Brazil as cachandiá. The potential threat to biodiversity, due to possible genetic contamination, competition and predation of wild stocks, of such artificially produced hybrid fishes is discussed.     

Length–weight relationships and length at first maturity for fish species in the upper Miranda River,southern Pantanal wetland,Brazil

Length–weight relationships (LWR) were estimated for 17 species and total length at first maturity (L50) for three species of freshwater fishes from the Miranda River, southern Pantanal, Brazil. The b values were compared for some species in the Paraguay River basin with the northern (Cuiabá River) part of the basin; differences in length–weight relationships were significantly different for Pseudoplatystoma corruscans, P. reticulatum (syn. P. fasciatum). First references on L50 and LWR are presented for two and eight fish species, respectively, as well as the new maximum total length for two species.     

Yellow-eyed piranhas produce louder sounds than red-eyed piranhas in an invasive population of Serrasalmus marginatus

Serrasalmus marginatus is a piranha species native from the lower Paraná River basin and has been invasive in the upper Paraná River basin since the 1980s. In piranhas, sounds of different species have different features. The aim of this study was to investigate if the sounds produced by this species could be used to distinguish two morphotypes: red- and yellow-eyed S. marginatus from the Araguari River (upper Paraná River basin). All the temporal and frequency features of the sounds were equivalent in both groups of eye colour; it corresponds to the species-specific signature described for S. marginatus. Nonetheless, the amplitude features were all statistically different between red- and yellow-eyed piranhas. Yellow-eyed specimens produced louder sounds. In different fish species, colour change in eyes can be due to the absence or the presence of a dominant allele. It can also be involved in social rank or during reproduction. Different hormones and neuropeptides can modulate vocal features. It is hypothesized that a mutation or different hormonal concentrations could explain both sound amplitude and eye colour playing a role in animal communication in S. marginatus.     

Patterns of population differentiation in annual killifishes from the Paraná–Uruguay–La Plata Basin: the role of vicariance and dispersal

Aim To elucidate the role of vicariance versus dispersal at the microevolutionary scale in annual killifish populations belonging to the Austrolebias bellottii species complex (Rivulidae). Within this complex, A. bellottii and A. apaii have low vagility and occur widely within the study area, making them excellent models for testing biogeographic hypotheses of differentiation. Location South America, in the Paraná–Uruguay–La Plata river basin. Methods Molecular data and morphometric analyses were used to reconstruct the phylogeographic history and morphological variation of 24 populations of two taxa of the A. bellottii species complex. Phylogenetic analyses using maximum likelihood (ML) and Bayesian inference (BI) model‐based methods, estimates of clade divergence times implemented in beast , non‐metric multidimensional scaling, analysis of molecular variance results, and morphological analyses elucidated the role of vicariance versus dispersal hypotheses in population differentiation in the aforementioned river basin. Results In the A. bellottii species complex from the Paraná–Uruguay–La Plata river basin, past allopatric fragmentation from vicariance events seems to be the most plausible scenario for diversification since the Late Miocene and more recently since the Plio‐Pleistocene. The Plio‐Pleistocene vicariance produced the differentiation of three major clades in A. bellottii populations. One clade from the eastern Uruguay River drainage was separated from another in western Uruguay and the Paraná–La Plata River drainages. A later vicariance event split populations to the south (lower Paraná–La Plata Basin) and north (middle Paraná) of the western Paraná River drainage. However, our results do not exclude the possibility of dispersal events among A. bellottii populations from both the Uruguay and Paraná river drainages, which could occur in these river basins during hypothesized connectivity cycles of the Late Pliocene and Pleistocene. Main conclusions Past allopatric fragmentation caused by different vicariance events seems to be the main driver of diversification in the A. bellottii species complex since the Plio‐Pleistocene. However, the current molecular data suggest that populations from both drainages of the Paraná–Uruguay rivers may have experienced cycles of connectivity during the Pleistocene, perhaps including multiple vicariance or dispersal events from populations located in the western lower Uruguay River drainage, which encompassed climatic and geological changes in the Paraná–Uruguay–La Plata Basin.     

<Emphasis Type="Italic">Monticellia santafesina</Emphasis> n. sp. (Cestoda: Proteocephalidea), a parasite of <Emphasis Type="Italic">Megalonema platanum</Emphasis> (Günther) (Siluriformes: Pimelodidae) in the Paraná River basin,Argentina

The proteocephalidean tapeworm Monticellia santafesina n. sp. is described from the siluriform catfish Megalonema platanum (Günther) (Siluriformes: Pimelodidae) in the Paraná River basin, Argentina. The new species is allocated to Monticellia La Rue, 1911 (Proteocephalidae: Monticelliinae) because of the cortical position of the testes, ovary, vitelline follicles and uterus, a globular scolex without a metascolex and uniloculate suckers. The new species differs from all other species of Monticellia (except for M. lenha Woodland, 1933) in possessing a vaginal canal opening anterior or posterior to the cirrus-sac. M. santafesina can be distinguished from M. lenha by the following characteristics: a larger body size; a weakly developed internal longitudinal musculature arranged in 15–35 slim bundles of muscle fibres; vitelline follicles not interrupted at the level of the cirrus-sac and vaginal canal, and with a few paramuscular and/or medullary follicles; the absence of large spinitriches on the anterior margin of the suckers; and the utilisation of Megalonema platanum (in the Paraná River basin) as its host, rather than Sorubimichthys planiceps (Spix & Agassiz) (in the River Amazon). Monticellia santafesina exhibits low values of prevalence (9%) and intensity of infection (1). Megalonema platanum was parasitised by two proteocephalidean cestodes, Rudolphiella cf. lobosa (Riggenbach, 1895) and the new species described in this paper.     

Length–weight relationships of two catfish species from the Guareí River basin,São Paulo,Brazil

Here the length–weight relationships (LWRs) of two catfish species are provided. Individuals of Imparfinis mirini Haseman, 1911, and Phenacorhamdia tenebrosa (Schubart, 1964) were collected in August and December 2017 from the Guareí River Basin, upper Paraná River basin, Brazil. Values of b were between 2.66 and 3.11 and a between 0.0122 and 0.0137; statistical analysis showed high r² values. Lastly, a new record of maximum standard length for P. tenebrosa is provided.     

Heavy metal content and response of the blood system of Siberian dace <Emphasis Type="Italic">Leuciscus leuciscus baicalensis</Emphasis> (Cypriniformes,Cyprinidae) under anthropogenic impact

Chemical, hematological, and immunological characteristics of the Siberian dace Leuciscus baicalensis from different areas of Lake Baikal basin were first determined. It was established that the most considerable changes in hemopoesis, cellular, and humoral links of immunity were in individuals with a high content of heavy metals in the liver from populations inhabiting the Selenga River downstream the Ulan Ude Industrial Center and the Selenga Pulp-and-Cardboard Plant. Changes in immunohematological responses of L. leusiscus baicalensis from Cherkalov Bay of Lake Baikal proceeded within the adaptive possibilities of the species and indicated the development of compensatory reactions in response to the accumulation of heavy metals in the body. The results obtained make it possible to assert that Chivurkuiskii Bay of Baikal may serve as a control polygon during monitoring of immunobiological states of fish populations from Baikal basin.