Reproduction of the annual fish Austrolebias nigrofasciatus (Rivulidae) maintained at different temperatures

Temperature is considered an important factor that influences the life cycle of annual fishes, however the thermal preferendum of Austrolebias nigrofasciatus reproduction has not been defined. The hypothesis was that the fecundity of the species would respond differently within the temperature range analyzed, presenting an optimum thermal. Thus, this study investigated the effect of temperature on the fecundity of A. nigrofasciatus for the first time under laboratory conditions. Pairs of A. nigrofasciatus were placed in aquaria with temperatures of 17, 21 or 25°C, with four pairs (replicates) for each treatment, for five weeks. Contrary to expected, there were no significant differences in fecundity parameters among the tested temperatures, but the weekly fecundity at 17 and 21°C was more homogeneous than at 25°C. During the experimental period, the temperature did not affect male growth; however, at 25°C there was a negative effect on female body growth. The condition factor was also influenced, suggesting a tendency towards a negative energy balance with increasing temperature. The results indicate that temperatures between 17 and 21°C are suitable for broodstock maintenance.     

Evidences for genetic differentiation within the highly endemic and endangered annual fish Austrolebias nigrofasciatus (Cyprinodontiformes: Rivulidae)

Samples of Austrolebias nigrofasciatus (n = 103), an endangered species of annual fish endemic to a small area of the Patos-Mirim lagoon system encompassing the São Gonçalo Channel lowlands, were collected from eight isolated temporary ponds, four located at the known distribution range of the species and four located along the Piratini River lowlands, where morphologically different individuals were found. In the laboratory, fragments of the mitochondrial cytochrome c oxidase I (coI), cytochrome b (cytb) and nuclear rhodopsin (rho) genes were amplified, purified and sequenced for 100, 99 and 58 of these individuals, respectively. Samples were further analysed using phylogenetic and phylogeographic methods to evaluate the patterns of genetic diversity and differentiation presented within and between populations, while assessing their evolutionary history, in order to guide the application of further conservation strategies. We found that the four new populations from the Piratini River lowlands encompass a different lineage of A. nigrofasciatus that diverged from that encountered in the São Gonçalo Channel at approximately 0.165 M years before present, during a population expansion and did not yet attain reciprocal monophyly. This divergence was associated with a glacial event that was preceded by an interglacial period putatively associated with the dispersal. Moreover, significant levels of genetic differentiation and a high number of exclusive haplotypes could be encountered even in micro-geographical scales, as in the comparisons between populations located within the same major lineage, indicating each of them may encompass independent management units. Conservation actions are certainly urgent, especially in the face of signs of a recent bottleneck.     

An update on the status of native and exotic freshwater fishes of Italy

An updated, corrected checklist of both native and established alien freshwater fish species in Italy is given based on molecular, morphological and biogeographical data. Some 12 native species, reported as conspecific with transalpine species in official Italian ichthylogical literature, are in fact endemics. Previous taxonomic confusion has resulted in the introduction of several alien species, either with official stockings or mixed in as impurities. Rehabilitated species include the cyprinids Scardinius hesperidicus, Scardinius scardafa and Telestes savigny from northern Italy, as well as Squalius ruffoi and the Telestes comes from southern Italy. Squalius albus is a junior synonym of S. squalus. The endemic gudgeon, previously assigned to the genus Romanogobio, is returned to the genus Gobio (G. benacensis). Phoxinus lumaireul is a junior synonym of P. phoxinus. Among the Salmonidae, Salmo cenerinus is a junior synonym of S. marmoratus, while Salmo farioides represents the trout species of the Adriatic lineage for which a neotype is designated. Thymallus aeliani represents the endemic lineage of grayling of the Adriatic populations. The esocid Esox cisalpinus is an endemic pike species and Esox flaviae is a junior synonym; the extensive exportation as well as the presence of this species throughout Europe is possibly due to humans. Among sculpins, Cottus scaturigo and C. ferrugineus are junior synonyms of C. gobio. The International Union for Conservation of Nature (IUCN) categories for native species of Italy are updated. At present, 52 native freshwater fish species are listed: 2 are extinct (Acipenser sturio and Huso huso), 12 are critically endangered, 7 endangered, 10 vulnerable, 3 near‐threatened, 15 low concern and 3 data‐deficient; 35 species are the result of human transfers. Among the 51 introduced species, 6 are recently established (Leuciscus leuciscus, Oreochromis niloticus, Poecilia reticulata, Xiphophorus helleri, Amatitlania nigrofasciatus, Hemichromis sp.), 37 are already established, 5 are probably established and 3 are non‐established Chinese carp, maintained in the wild by intensive stockings. The family most involved is the Cyprinidae, with 22 alien and 20 native species.     

A comparison of the reproductive strategies of three species of Dysdercus from Africa (Hemiptera,Pyrrhocoridae)

Summary Reproductive strategies have been investigated for three species of Dysdercus from Africa, D. intermedius, D. cardinalis and D. nigrofasciatus. Reproductive parameters were measured for each species on individuals cultured in the laboratory. D. cardinalis is associated more with herbaceous than with arboreal host plants and is intermediate in body size. It tended to have the least age at first reproduction, reproduced most frequently, and layed the smallest clutches on average, spreading relatively high amounts of parental investment in more clutches than the other two species. It also laid the greatest number of clutches and eggs in a lifetime. D. intermedius specializes on arboreal host plants, and is the largest of the three species. It had the greatest age at first reproduction, reproduced less frequently than D. cardinalis, and layed the largest clutches. Its parental investment over time declined earlier than that of D. cardinalis. D. intermedius layed the least number of clutches in a lifetime, but its lifetime gross reproduction was intermediate in magnitude. D. nigrofasciatus has the widest diet breadth, and is the smallest in body size. Its age at first reproduction was similar to that of D. cardinalis, but D. nigrofasciatus reproduced least frequently, laying relatively large clutches. It was similar to D. intermedius in its pattern of parental investment over time, and essentially layed the same number of clutches in a lifetime as the latter species, although its lifetime gross reproduction was the smallest.It is suggested that the reproductive strategies of the three species might have evolved as adaptations to selection events in the niches of the immature stages.     

Neurohormones as putative circadian clock output signals in the central nervous system of two cricket species

Antisera to the neuropeptides corazonin (Crz) and crustacean cardioactive peptide (CCAP) and to the diapause hormone (DH) react with small sets of neurones in the cephalic ganglia of the crickets Dianemobius nigrofasciatus and Allonemobius allardi. The distribution of their immunoreactivities is similar in the two species and overlaps with the locations of presumed circadian clock components in the optic lobes, protocerebrum, tritocerebrum, suboesophageal ganglion (SOG) and frontal ganglion. D. nigrofasciatus contains two Crz-immunoreactive (Crz-ir) cells in each optic lobe, six cell groups in the protocerebrum, four in the tritocerebrum, and one in SOG, whereas A. allardi harbours only five Crz-ir groups in the protocerebrum and four in the tritocerebrum. CCAP immunoreactivity occurs in both species in four protocerebrum cell clusters, four tritocerebrum cell clusters, four SOG cell clusters, one frontal ganglion cell cluster, and two optic lobe cell clusters; D. nigrofasciatus possesses two additional cells with unique links to the lamina in the optic lobe. DH-related antigens are present in four cell clusters in the optic lobe, six (D. nigrofasciatus) or eight (A. allardi) in the protocerebrum, four in the tritocerebrum, and three (A. allardi) or five (D. nigrofasciatus) in the SOG. Some of the detected cells also react with antibody to the clock protein Period (PER) or lie close to PER-ir cells. Crickets reared at two different photoperiods do not differ in the distribution and intensity of immunoreactivities. No changes have been detected during the course of diurnal light/dark cycles, possibly because the antisera react with persistent prohormones, whereas circadian fluctuations may occur at the level of their processing or of hormone release. The projection of immunoreactive fibres to several brain regions, the stomatogastric nervous system and the neurohaemal organs indicates multiple functions of the respective hormones. The work was supported by the “Research for Future” program of the Japan Society for the Promotion of Science (JSPS, 99L01205) and by the JSPS Postdoctoral Fellowship for Foreign Researchers (no. P 04197).     

Experimental studies of migration in bugs of the genus Dysdercus

Summary Using a tethered flight technique, migration was studied in the African cotton stainer bugs Dysdercus fasciatus Sign., D. nigrofasciatus Stål, and D. superstitiosus (F.) (Heteroptera: Pyrrhocoridae). The flight system of males of all three species matures in 4–6 days post-eclosion, and flight can continue throughout life. Fed females of D. fasciatus do not fly, but rather histolyse the flight muscles and develop oocytes. Fed females of D. nigrofasciatus and D. superstitiosus exhibit some flight at 4 days post-eclosion, but flight is essentially absent at 6 days when flight muscle histolysis and oögenesis are in progress. Starved females of all three species undertake considerable flight and do not histolyse the flight muscles or develop oöcytes. In starved pairs coupling frequency is lowered permitting increased migration. The three species are thus facultative migrants using starvation as a releasing cue. D. fasciatus feeds on baobab (Adansonia) fruits which are seasonally abundant and is the most opportunistic species with the highest reproductive potential and no flight in the presence of food. D. nigrofasciatus feeds on a variety of herbaceous annuals and perennials; it follows an intermediate migration and reproductive strategy. Finally D. superstitiosus is the most catholic in its food habits and has the lowest reproductive potential. Both of the latter species retain some flight capacity even when fed, presumably so that individuals can locate suitable host plants.     

Diagnostic features and biometry of head bones for identifying Carassius species in faecal and archaeological remains

The identification of fish species from head bone remains is employed in various sciences, including archaeology, paleontology and field ecology, with the estimation of fish size from biometric relationships being useful in the assessment of predation pressure exerted by increasing numbers of piscivorous species (e.g. Eurasian otter Lutra lutra and great cormorant Phalacrocorax carbo). This is particularly relevant for crucian carp, Carassius carassius, which is in decline in Europe due to changes in land use and to increasing numbers of non‐native Carassius species (i.e. goldfish C. auratus, gibel carp C. gibelio), which hybridize with C. carassius. However, diagnostic keys and biometric relationships are lacking for C. carassius and its most common hybrids, crosses with C. auratus. The present paper addresses this gap in knowledge, providing diagnostic keys and biometric relationships for the head bones of all Carassius species found in Europe as well as for C. carassius × C. auratus hybrids. All bone size to body length relationships were statistically significant. Similarly, all bone size to body weight relationships were significant for C. carassius, C. auratus, and C. gibelio, but none were significant for C. carassius × C. auratus hybrids. Diagnostic structures were found to distinguish easily between the Carassius species and hybrids, which will assist in determining the identity and sizes of prey found in faecal and archaeological remains.     

A molecular phylogeny of the north‐east Atlantic species of the genus Idotea (Isopoda) with focus on the Baltic Sea

Today, the marine isopods of the genus Idotea Fabricius, 1798 consist of 26 accepted species. Most species can be found in the Northern Hemisphere. While some species have a cosmopolitan distribution, others are endemic to a few coastlines. In the Baltic Sea, Idotea species have a key role as important meso‐grazers. Only three species can be found in this brackish environment, I. balthica, I. chelipes and I. granulosa, while nine species are described from the whole European coast. The goal of the present study was to reconstruct the phylogeny of the genus Idotea and to test whether the Baltic low‐salinity tolerant species represent a single lineage within the genus. The phylogeny of north‐east Atlantic Idotea species was investigated based on a fragment of the nuclear gene 28S and the mitochondrial gene COI for eight Idotea species. The phylogenetic reconstructions showed that the genus Idotea might not be monophyletic. Neither I. linearis nor I. urotoma did belong to the separated and well‐supported Idotea clade of I. balthica, I. chelipes, I. emarginata, I. granulosa, I. metallica and I. pelagica. The three Idotea species found in the Baltic belonged to different lineages, with estimated COI‐based divergence time older than 7 Myr. This suggests that the tolerance to low salinity has likely evolved in the genus Idotea more than once.     

Predicting invasion risk of 16 species of eucalypts using a risk assessment protocol developed for Brazil

Risk analyses are predictive systems designed to detect the risk of invasion by non‐native species. Although eucalypts are often considered moderately invasive given the extent of cultivation on a global scale, some species are widely recognized as invasive for transforming and impacting natural areas in several countries. These problems may be due to propagule pressure derived from human interest in forest production and aesthetic values. Risk analyses were carried out for 16 eucalypt species cultivated in Brazil using a protocol adapted from an Australian model to Brazilian conditions. The species were: Corymbia citriodora, Corymbia maculata, Corymbia torelliana, Eucalyptus benthamii, Eucalyptus brassiana, Eucalyptus camaldulensis, Eucalyptus cloeziana, Eucalyptus dunnii, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus pellita, Eucalyptus robusta, Eucalyptus saligna, Eucalyptus tereticornis, Eucalyptus urophylla and Eucalyptus viminalis. Results indicate high risk for seven species, moderate risk for eight species and low risk for one species. The only low risk species is E. dunnii, while the highest risk scores refer to C. torelliana, E. tereticornis and E. grandis. These results are consistent with the history of invasion of the species around the world and should be considered for plantations especially when investment capacity to prevent and permanently control spread is low or not associated with forest certification standards. Risk analysis is a valid tool for discriminating between species and making decisions on species to be introduced or cultivated. The results of this study show that there are many species that can be cultivated without incurring biological invasions.     

Microsatellite markers for European Daphnia

We present 32 polymorphic microsatellite markers for species of the European Daphnia longispina group: D. galeata, D. hyalina, D. rosea, D. cucullata and D. curvirostris. Microsatellite markers were either isolated from genomic libraries or optimized based on previously published sequence information of sister taxa. Cross‐species tests revealed that all but one of the polymorphic markers are applicable to more than one species, which allows intra‐ and interspecific genetic studies on, i.e. population structure, hybridization events and introgression.     

Evolution of the African slippery frogs (Anura: Conraua), including the world’s largest living frog

Although Conraua goliath is well known as the largest living frog species, the diversity and evolution of the genus Conraua across sub-Saharan Africa remain poorly understood. We present multilocus phylogenetic analyses of the six currently recognized species that provide insights into divergence times, biogeography, body size evolution and undescribed species. An analysis of divergence times demonstrates that crown-group Conraua arose some time during the latest Oligocene to mid-Miocene followed by divergence into major lineages in the mid-Miocene that may reflect the fragmentation of widespread tropical forests in Africa that began at this time. We find three pairs of sister species, C. crassipes + C. beccarii, C. alleni + C. derooi and C. goliath + C. robusta, each of which diverged during the Miocene. These relationships reject phylogenetic hypotheses based solely on biogeography as the geographically peripheral C. beccarii from north-eastern Africa is nested within western African species and the Central African species do not form a clade. Our species delimitation analyses provide support for undescribed species in C. alleni, C. beccarii and C. derooi, and possibly C. crassipes, suggesting that the current taxonomy substantially underestimates species diversity. There is no clear directional trend of either increasing or decreasing body size in Conraua and the three largest species do not form a clade. With a robust phylogenetic hypothesis in hand, further field-based studies are needed to understand the evolution of morphology and life history in this charismatic African anuran clade.     

Molecular phylogeny of African hinge‐back tortoises (Kinixys): implications for phylogeography and taxonomy (Testudines: Testudinidae)

We examine the phylogeography, phylogeny and taxonomy of hinge‐back tortoises using a comprehensive sampling of all currently recognized Kinixys species and subspecies and sequence data of three mitochondrial DNA fragments (2273 bp: 12S rRNA, ND4 + adjacent DNA coding for tRNAs, cytb) and three nuclear loci (2569 bp: C‐mos, ODC, R35). Combined and individual analyses of the two data sets using Bayesian and Maximum Likelihood methods suggest that the savannah species of Kinixys are paraphyletic with respect to the rainforest species K. homeana and K. erosa, and that the rainforest species may be derived from a savannah‐living ancestor. The previously recognized savannah species K. belliana was a conglomerate of three deeply divergent clades that we treat here as distinct species. We restrict the name K. belliana (Gray, 1830) to hinge‐back tortoises ranging from Angola to Burundi, while five‐clawed hinge‐back tortoises from the northernmost part of the formerly recognized range of K. belliana, together with four‐clawed tortoises from West Africa, are assigned to the species K. nogueyi (Lataste, 1886). These two species are allied to K. spekii, whereas Southeast African and Malagasy hinge‐back tortoises formerly lumped together with K. belliana represent the distinct species K. zombensis Hewitt, 1931, which is sister to K. lobatsiana. The latter two species together constitute the sister group of the rainforest species K. homeana and K. erosa. Mitochondrial data suggest that K. natalensis has a basal phylogenetic position in a clade embracing K. belliana sensu stricto, K. nogueyi and K. spekii, while nuclear data and the two data sets combined favour a sister group relationship of K. natalensis to all other hinge‐back tortoises. Phylogeographic structure is present in all wide‐ranging species and correlates in K. homeana and K. erosa with the Dahomey Gap and former rainforest refugia. The Malagasy population of K. zombensis is weakly differentiated from its South African conspecifics and further sampling is needed to determine whether there is support for the subspecific distinctness of Malagasy tortoises.     

Revision of the South American wasp genus Aelurus (Hymenoptera: Tiphiidae: Thynninae)

Abstract. The relationships among the thirteen South American species of Aelurus are discussed, and nine new species are described. New synonymy is given for gayi (Spinola), clypeatus Klug and nigrofasciatus (Smith).     

Length–weight relationships of six fish species from the headstream region of the Dongjiang River,China

Dongjiang River, a main tributary of the Pearl River, is geographically situated in South China. The present study describes the length–weight relationships (LWRs) of six fish species (Acrossocheilus paradoxus, Barbodes semifasciolatus, Onychostoma elongatum, Microphysogobio fukiensis, Microphysogobio kiatingensis, Metzia lineata) from the headstream region of the river including five Chinese endemic species (A. paradoxus, B. semifasciolatu, O. elongatum, Mi. fukiensis, Mi. kiatingensis). Fish species of five genera of the same family were collected quarterly from April 2012 to October 2014 by using non‐selective fishing gears: drag nets (5 m, mesh‐size 3 cm), drift gillnets (30 × 15 m, mesh‐size 5 mm), fish cages (4 m, mouth opening 40 × 40 cm), scoop nets (mesh‐size 0.5‐1 cm), and electro‐fishing (12V, 200 Hz). The parameter a and b in the LWR equations (W = a L^b) ranged from 0.0014 to 0.0228, and 2.89 to 3.18, respectively. Compared with FishBase, this study provides the first LWR records for four cyprinids (A. paradoxus, B. semifasciolatu, O. elongatum, Me. lineata) and a new record of maximum body length for O. elongatum.     

Karyotypic differentiation via 2n reduction and a finding of a case of triploidy in anurans of the genus <Emphasis Type="Italic">Engystomops</Emphasis> (Anura,Leiuperidae)

The genus Engystomops is divided into two groups, namely the Duovox clade and the Edentulus clade. The species of Edentulus clade have karyotypes with 2n = 22, while E. pustulatus and E. puyango, which belong to Duovox clade, have 2n = 20. To investigate if 2n = 20 is a synapomorphy of Duovox clade, we cytogenetically analyzed all the species of this group, except for E. puyango, in the present study. All of them had 2n = 20, differing from the species of Edentulus clade. Since the species already karyotyped of the genus Physalaemus, which is considered to be the sister group of Engystomops, also have 2n = 22, we conclude that the 2n reduction is a synapomorphy of Duovox clade. Despite the karyotypes of all the species of Duovox clade were very similar, they varied in the NOR pattern. In E. coloradorum, an additional NOR was found in one homologue of the chromosome pair 10 exclusively in all females, indicating that this could possibly be a sexual pair of the ZZ/ZW system. Also in this species, it was found the first case of natural polyploidy of the genus Engystomops.     

Seasonal dynamics in community structure,abundance, body size and sex ratio in two species of Neotropical annual fishes

Seven ephemeral pools on the coastal plain of southern Brazil were found to be inhabited by three annual and 22 non‐annual fish species. Two common annual species (Austrolebias minuano and Cynopoecilus fulgens) exhibited clear seasonal dynamics, with the appearance of young fishes in the austral autumn (May to June) and a decline in abundance over the seasonal cycle. The third annual species, Austrolebias wolterstorffii, was rare. No seasonal dynamics were observed in non‐annual fishes. The relative abundance of non‐annual fishes compared with annual fishes increased over the seasonal cycle, but they coexisted widely. The size structure of annual fishes suggested the presence of a single age cohort in most pools though a second age cohort was registered in one pool in August, coinciding with a large flooding. Strong sexual dimorphism in body size was found in C. fulgens throughout the seasonal cycle, while no sexual dimorphism in body size was found in A. minuano. Female‐biased sex ratios were recorded in both common annual fish species in the last three sampling dates (in spring), but not during the first two sampling dates (in winter). The natural lifespan of annual fishes was <8 months. Annual fishes disappeared before habitat desiccation in half of the pools, while non‐annual fishes were still present.     

Molecular phylogeny of the New World gecko genus Homonota (Squamata: Phyllodactylidae)

The genus Homonota was described by Gray (1845) and currently includes 10 species: Homonota andicola, H. borellii, H. darwinii, H. fasciata, H. rupicola, H. taragui, H. underwoodi, H. uruguayensis, H. williamsii & H. whitii and one subspecies of H. darwinii (H. darwinii macrocephala). It is distributed from 15° latitude south in southern Brazil, through much of Bolivia, Paraguay, Uruguay and Argentina to 54° south in Patagonia and across multiple different habitats. Several morphological taxonomic studies on a subset of these species have been published, but no molecular phylogenetic hypotheses are available for the genus. The objective of this study is to present a molecular phylogenetic hypothesis for all the described species in the genus. We sequenced two mitochondrial genes (cyt‐b & 12S: 1745 bp), seven nuclear protein coding (RBMX, DMLX, NKTR, PLRL, SINCAIP, MXRA5, ACA4: 5804 bp) and two anonymous nuclear loci (30Hb, 19Hb: 1306 bp) and implemented traditional concatenated analyses (MP, ML, BI) as well as species‐tree (*beast ) approaches. All methods recovered almost the same topology. We recovered the genus Homonota as monophyletic with strong statistical support. Within Homonota, there are three strongly supported clades (whitii, borellii and fasciata), which differ from those previously proposed based on scale shape, osteology, myology and quantitative characters. Detailed morphological analyses based on this highly resolved and well‐supported phylogeny will provide a framework for understanding morphological evolution and historical biogeography of this phenotypically conservative genus. We hypothesize that extensive marine transgressions during Middle and Late Miocene most probably isolated the ancestors of the three main clades in eastern Uruguay (borellii group), north‐western Argentina‐southern Bolivia (fasciata group), and central‐western Argentina (whitii group). Phylogeographic and morphological/morphometric analyses coupled with paleo‐niche modelling are needed to better understand its biogeographical history.