Hand Nets Research Articles

Gökçeada içsularının Amphipoda (Crustacea: Malacostraca) faunası

In order to determine the Amphipod species inhabited the inland waters of the Gökçeada Island, which is the biggest island of Turkey in the Aegean Sea, samples were sampled from 17 localities in different dates, were carried out. Samples were collected with 500 µm mesh-sized hand nets and were fixed in 4% formalin solution in field. As a result, three species [Gammarus komareki Schäferna 1922, Gammarus aequicauda (Martynov, 1931) and Orchestia mediterranea Costa, 1853] belonging to Gammaridae and Talitridae families were determined. All of the three species are newly recorded from Gökçeada Island.

Natural exposure of bats in Grenada to rabies virus

ABSTRACT Introduction: Grenada is a rabies endemic country, where terrestrial rabies is maintained in the small Indian mongoose (Herpestes auropunctatus). The role of bats in the epidemiology of rabies in Grenada is unknown. A 1974 report described one rabies virus positive Jamaican fruit bat (Artibeus jamaicensis), and a high seroprevalence in this species. In the current study, the natural exposure to rabies virus in Grenadian bats was re-evaluated. It is postulated that bats serve as a natural rabies reservoir, probably circulating a bat-specific rabies virus variant. Material and methods: Bats were trapped in 2015 in all six parishes of Grenada using mist- and hand nets. For the detection of rabies virus in brain tissue, the direct fluorescent antibody test (dFAT) and the reverse transcription polymerase chain reaction (RT-PCR) were used. Serum neutralizing antibodies were determined using the fluorescent antibody virus neutralization test (FAVN). Results and discussion: Brain tissue and sera from 111 insectivorous and frugivorous bats belonging to four species were tested (52 Artibeus jamaicensis, two Artibeus lituratus, 33 Glossophaga longirostris, 24 Molossus molossus). Rabies virus antigen and genomic RNA were not detected in brain tissues. Rabies virus neutralizing antibodies were detected in the sera of eight A. jamaicensis in four of the six parishes. Bats in Grenada continue to show natural exposure to rabies virus. As rabies virus was not isolated in this study, serology alone is not sufficient to determine the strain of rabies virus circulating in A. jamaicensis bats in Grenada. Conclusion: Artibeus jamaicensis appears to play a role as a reservoir bat species, which is of public health concern in Grenada. Dispersion of bats to neighboring islands is possible and serological bat surveys should be initiated in these neighboring states, especially in those areas that are free of rabies in terrestrial mammals.

Fishes from the Jaru Biological Reserve, Machado River drainage, Madeira River basin, Rondônia State, northern Brazil

Abstract: This work assessed freshwater fishes collected at 12 stations located along the Tarumã River, middle Machado River, Madeira River basin. The fieldwork took place in May and September 2015 during the high and low water seasons, respectively. We gathered 1,482 specimens representing seven orders, 30 families, 54 genera and 74 species using seine, gill, and hand nets. The family Characidae was the most representative, exhibiting the highest number of species captured. The species with the greatest abundance were Hemigrammus vorderwinkleri, Hyphessobrycon bentosi, Hemigrammus cf. bellottii, Bryconella pallidifrons, and Apistogramma resticulosa. Two species that remained unidentified are probably a new species. This study represents the third fish survey totally conducted at a Conservation Unit in the Rondônia State, and will certainly provide valuable information for future investigations on biodiversity conservation in the Machado River.

Diets, population structure, and seasonal activity patterns of mudpuppies ( Necturus maculosus ) in an urban, Great Lakes coastal habitat

Freshwater species native to the Laurentian Great Lakes region face numerous environmental stressors, and the conservation status and ecological relationships of many remain poorly understood. One such species, the mudpuppy (Necturus maculosus), is declining, but better information on their natural history and development of more effective population monitoring techniques is needed. We assessed seasonal variation in capture success, biases in capture techniques, and feeding ecology of mudpuppies in Wolf Lake, a highly perturbed and urban former estuarine wetland complex to Lake Michigan. Trapping periods of ≥ 3 consecutive nights occurred from January to May 2015, and October 2015 to March 2016. Overall trapping success differed among trapping periods (p = 0.01) and declined precipitously at water temperatures above 14.1 °C (p < 0.001). Mudpuppies in traps (mean 26.9 ± 0.5 cm) were larger than those caught with hand nets (mean 14.7 ± 0.8 cm, p < 0.0001), suggesting that multiple methods may be needed to accurately assess demographics. Stomach contents obtained through gastric lavage included mollusks, leeches, insects, isopods, amphipods, crayfish, fish, a frog, and a juvenile conspecific. Invasive species, including rusty crayfish (Orconectes rusticus), round gobies (Neogobius melanostomus), and zebra/quagga mussels (Dreissena spp.) were present in guts, suggesting mudpuppy foraging has changed along with aquatic communities in the region. Prey community analyses revealed differences in overall diet among size classes of mudpuppies (p = 0.001), but relatively weak similarity within size classes. Results suggest that mudpuppies in lake ecosystems occupy a broad niche that changes as they grow.

Bee-friendly community gardens: Impact of environmental variables on the richness and abundance of exotic and native bees

With their abundant floral resources, urban community gardens have the potential to play an important role in pollinator conservation. At the same time, the gardens themselves are dependent upon the pollination services provided by insects. Thus, understanding the variables that can increase bee richness or abundance in community gardens can contribute to both urban agriculture and pollinator conservation. Here we examine the impact of several environmental variables on bee abundance and diversity in urban community gardens in Sydney, Australia. We used hand netting and trap nests to sample bees in 27 community gardens ranging from inner city gardens with limited surrounding green space, to suburban gardens located next to national parks. We did not find strong support for an impact of any of our variables on bee species richness, abundance or diversity. We found high abundance of a recently introduced non-native bee: the African carder bee, Afranthidium repetitum (Schulz 1906). The abundance of African carder bees was negatively correlated with the amount of surrounding green space and positively correlated with native bee abundance/species richness. Our results highlight the seemingly rapid increase in African carder bee populations in inner city Sydney, and we call for more research into this bee’s potential environmental impacts. Our results also suggest that hard-to-change environmental factors such as garden size and distance to remnant forests may not have a strong influence on native bee diversity and abundance in highly urbanized area.

Pemetaan Habitat Ruaya Benih Ikan Sidat (Anguilla bicolor) dan Potensinya di Pantai Selatan Jawa

The eels is fish commodities that interesting and prospective for cultured. For the fish fry supply stillrely on catches of wild nature, one of them the south coast of Java. But the these habitat andabundance not yet to mapping The aims of this study to assess the conditions migration habitat ofglass eel, abundance, identification of threats, and conservation efforts. The study used surveymethods, glass eel catched with hand nets size 1 x 1 m, catching at night each 2 hours, thenumber of fisherman are three peoples. The results of the study recorded nine rivers and four ofthem potential as migration habitat of eels, habitat conditions are still good, the highest abundanceis Cibuniangen river in the rainy season, the daily abundance was fluctuated and the highest at3:00 a.m, identified several threats, conservation need integrated effort.Keywords: eels, habitat, abundance, conservation

Benthic macroinvertebrate of Adıgüzel Reservoir (Denizli, Turkey)

In order to determine the benthic macro-invertebrates of Adiguzel Reservoir, samplings were performed between January 2007 and December 2007 at four stations in dam lake and littoral zone. During the samplings, an Ekman Grab was used in those stations located in dam lake and 180 µ mesh sized hand nets were used in coastal samplings. Collected material were fixed in 4% formolin solution in field and then washed and sorted, identified and counted in laboratory.As a result of the study, totaly six species were determined. Of them, three belong to Diptera ( Chironomus tentans, Polypedilum nubeculosum, Procladius (Holotanypus) sp. ), two to Malacostraca (Paramysis kosswigi, Pontogammarus robustoides ) and one belongs to Oligochaeta ( Nais pardalis ). All of the determined species were firstly reported from the locality. The profundal zone of the Adiguzel Reservoir was poor in terms of productivity and the average chironomid density was 17 ind/m2. The remaining benthic macroinvertebrate species determined in this study were sampled from the littoral zone of the dam lake. Keywords: Benthic macroinvertebrate, Adiguzel Reservoir, Denizli, Turkey

Observations on the Chironomidae and Chaoboridae (Diptera) fauna of the Mountain Lakes in Denizli (Turkey)

In order to determine the Chironomidae and Chaoboridae fauna of Kartal Lake, Karagöl and Gökçeova Pond, samplings were performed in the summer months of 2009-2011. Benthic samples were collected from the littoral and profundal zones of the water bodies by using 180 µ mesh sized hand nets and Ekman Birge grab, respectively. As a result of the taxonomic study, totally 27 species were determined; of them 26 belong to five submailies (Tanypodinae, Prodiamesinae, Diamesinae, Orthocladiinae, Chironominae) of Chironomidae and one to Chaoboridae. The Chironominae subfamily was the dominant group with 16 taxa and was followed by Tanypodinae with 5 taxa. All the determined taxa were firstly recorded from the studied localities. This study aims to add a new one to our country’s mountain lakes studies and to determine common specimens which are unique for this environment characteristics. Keywords: Chironomidae, Chaoboridae, benthos, mountain lakes

Freshwater fish diversity in an oil palm concession area in Mimika, Papua

Ohee HL. 2016. Freshwater fish diversity in an oil palm concession area in Mimika, Papua. Biodiversitas 17: 665-672. New Guinea’s freshwater fish diversity may reach 400 species, twice the number of fish recorded in Australia. However, New Guinea’s freshwater fishes are facing rapid and poorly-planned social and economic developments, which have accelerated both habitat loss and degradation, impacting its unique biodiversity and threatening natural ecosystems. This study documents freshwater fish diversity and threats due to habitat conservation from oil palm development in the Timika Region, Papua. Fishes were sampled in canals, creeks, streams and rivers in the concession area of Pusaka Agro Lestari Company (PT. PAL) using seine and hand nets and a spear gun. Twenty two freshwater fish species in 15 families and 15 genera were recorded from the area. One of them is an endemic species ofTimika (Glossamia timika), one rainbowfish species with a restricted Southern New Guinea distribution, and 12 other native fishes. Land clearing leads to increase water turbidity and sedimentation, water temperature, and pollution which are potential threats to native fishes and their habitats. The fact that PAL’s concession is part of distribution area of known distribution of G. timika in Timika vicinity, habitat conversion to palm oil elevates the threat to this species. Hopefully, PT. PAL will adopt necessary conservation measures to mitigate the potential impact during the land clearing, especially, if they leave riparian buffer regions intact to protect aquatic habitats when clearing land.

Selectivity of Two Methods for Surveying the Japanese Mitten Crab, Eriocheir Japonica (De Haan, 1835), in a Riverine Environment

Differences between the results of pot fishing and hand-net collecting of the Japanese mitten crab, Eriocheir japonica (De Haan, 1835), were examined to increase the accuracy of sampling natural population in freshwater and tidal areas of a small river. Large adult crabs were caught in pots; small juveniles mostly collected with the hand nets. The difference in size composition in the freshwater river is probably caused by changes in the dietary preferences and behaviors that occur as crabs grow larger. The sex ratio was strongly male-biased in pot fishing in the tidal river in contrast to hand-net collecting (no bias), and males captured in the pots were slightly larger than those caught by hand-nets. The sex ratio bias observed in pot fishing in the tidal river can be explained by mating behavior, whereas the differences in the size of males between the two methods can be explained by the dimorphism and alternative mating strategy of male E. japonica . The proportions of ovigerous females in the tidal river in early winter were larger in pot than in hand-net samples. Differences in the proportion of ovigerous females between the two gears in the tidal river may have resulted from the presence of two groups differing in reproductive season and the wandering activities of ovigerous and non-ovigerous females. Although pot fishing is useful for studying reproductive ecology, the resulting data is sometimes strongly biased. In contrast, hand-net collecting is essential for gathering a complete range of crabs from all size classes and the data generated by this method is more representative of their distribution pattern. It is necessary to make up for the shortcoming of each sampling method.

Parasites component community in wild population ofPterophyllum scalareSchultze, 1823 andMesonauta acoraCastelnau, 1855, cichlids from the Brazilian Amazon

Summary The aim of the present study was to compare the component parasite communities of the Pterophyllum scalare and Mesonauta acora cichlids in the Amazon River system in northern Brazil. From September to December 2012, 42 specimens of P. scalare and 38 specimens of M. acora were captured using hand nets and gillnets in the Igarape Fortaleza basin, a tributary of the Amazon River in the state of Amapa. Of the P. scalare specimens examined, 97.6% were parasitized by Ichthyophthirius multifiliis, Tripartiella sp., Trichodina nobilis, Gussevia spiralocirra, Posthodiplostomum sp., Capillaria pterophylli, Ichthyouris sp. and Gorytocephalus spectabilis. Similarly, all specimens of M. acora were parasitized by I. multifiliis, Tripartiella sp, T. nobilis, Sciadicleithrum joanae, Posthodiplostomum sp., Pseudoproleptus sp., Ichthyouris sp. and G. spectabilis. However, for both hosts the dominance was of I. multifiliis and with an overdispersion of parasites. Parasite communities of P. scalare and M. acora were similar and only Pseudoproleptus sp. and Posthodiplostomum sp. were larvae. Brillouin diversity, parasite species richness and evenness were higher for M. acora than for P. scalare, which presented a negative correlation of parasite abundance with body size. Both cichlid species had parasite communities characterized by low diversity and low species richness, with a predominance of ectoparasite species and greatest richness of helminth species, with a low abundance of endoparasites. This was the first study on the parasite diversity in wild P. scalare and M. acora.

Luzonichthysseaver, a new species of Anthiinae (Perciformes, Serranidae) from Pohnpei, Micronesia.

Luzonichthys seaver, n. sp., is described from two specimens, 42-46 mm standard length (SL) collected from Pohnpei, Micronesia. Collections were made by divers on mixed-gas closed-circuit rebreathers using hand nets at depths of 90-100 m. Luzonichthys seaver is distinct from all other species of the genus in the characters of lateral line scales, gill rakers, pelvic fin length, caudal concavity and coloration. Of the six species of Luzonichthys, it appears to be morphologically most similar to L. earlei and L. whitleyi.

Feeding habits of mosquitoes (Diptera: Culicidae) in an area of sylvatic transmission of yellow fever in the state of São Paulo, Brazil.

BackgroundThe reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there also occurred an important epizootic. The purpose of this study was to investigate the feeding habits of culicids potentially involved in the sylvatic transmission of the virus in this region.MethodsSpecimens were collected in 24 forested localities at ground level with hand nets and mouth aspirators. Collections were made quarterly between October 2006 and July 2008 during daylight hours. Blood-meal identification was carried out in mosquitoes of the tribes Aedini, Mansoniini and Sabethini. The biotin/avidin sandwich ELISA was employed to determine six source types: bird, bovine, equine, rat, human and monkey.ResultsA total of 24,879 females of the three tribes were obtained, 245 (0.98%) of which were engorged. The presence of three different blood sources per engorged female was the predominant situation, and included 35.10% of the total of samples processed. Samples with two or four different sources were represented by 25.31% and 25.71%, of the specimens, respectively, while just 9.39% had only one type and 1.22%, five different sources. Aedes scapularis, Ae. serratus (Group), Psorophora albigenu and Ps. ferox were the most abundant species and accounted for about 95% of the engorged specimens. Of the principal vector species, Haemagogus janthinomys/capricornii was found with bird, bovine and primate blood. These sources were predominant and alternated top ranking as the most frequent source according to the mosquito species and collection site. In general, primate blood was the most prevalent source.ConclusionsThe human population of the region visits this ecotone frequently, which indicates the need for the periodical assessment of vaccination coverage against yellow fever. The frequency of non-human primate blood source in mosquito species that show minor vector importance in yellow fever virus transmission deserves attention. The eclectic feeding habits and some aspects of the interactions between potential vectors and reservoirs of yellow fever may be associated with the habitat fragmentation characteristic of the region. We recommend that further studies on the capacity and vector competence be performed on secondary vectors in extra-Amazonian region.Electronic supplementary materialThe online version of this article (doi:10.1186/s40409-015-0005-z) contains supplementary material, which is available to authorized users.

Fish die-off in the Attanagalu-Oya River, Sri Lanka: a provisional checklist of icthyofauna

Attanagalu Oya basin is situated between the two major river basins Kelani and Maha Oya in Western province of Sri Lanka and has an extent of 779 km2. It plays a major role in national water supply since it contains four major national water supply and drainage board intakes. This short communication intends to provide a recent report of fish die-off in the Attanagalu Oya and also include provisional checklist of icthyofaunal diversity in the area. The fish faunal data were collected from the catches of fishermen using cast nets, and hooks. In addition, fish in shallow areas were sampled by using small trawl nets and hand nets. Freshwater fish species were identified and classified by using published field guides and recent taxonomic research papers.

Shallow-water stenopodidean and caridean shrimps from Abrolhos Archipelago, Brazil: new records and updated checklist.

This study deals with a recent collection of stenopodidean and caridean shrimps made in the Abrolhos Archipelago, Bahia, Brazil, in July and August 2013. Sampling was carried out in the vicinity of Ilha de Santa Bárbara (17°57'49"S 38°41'53"W). Specimens were obtained by hand or using small hand nets in tide pools or under rocks in the intertidal zone. Part of the material was collected by scuba diving in the shallow subtidal, to a maximum depth of 11 m. We obtained a total of 18 species, 12 of which are reported for the first time for the Abrolhos and 4 as new records for the state of Bahia. The distributions of Microprosthema semilaeve (von Martens, 1872), Typton gnathophylloides Holthuis, 1951, Alpheus verrilli (Schmitt, 1924) and Alpheopsis cf. trigona (Rathbun, 1901) are extended from their previously known ranges. The occurrence of Automate cf. rectifrons Chace, 1972 on the Brazilian coast is confirmed. We thus provide an updated checklist of stenopodidean (2 species) and caridean (29 species) shrimps from the Abrolhos Archipelago, incorporating and critically evaluating previous records.

First Record of the anchialine shrimp Parhippolyte sterreri (Decapoda, Barbouriidae) from San Salvador Island, Bahamas, with observations on Barbouria cubensis

Sterrer's cave shrimp (Parhippolyte sterreri) is recorded for the first time from San Salvador Island, Bahamas. A single adult specimen was collected in June 2011 with hand nets at the southern conduit mouth in Mermaid Pond, an anchialine pond on the south-east corner of the island. Twelve additional specimens were collected in June 2013 from two additional sites near Mermaid Pond (Dunk City Pond and the Pigeon Creek Conduit). These collections represent a minor range extension ofP. sterreriin the Bahamas. Additionally, we report on populations ofBarbouria cubensisobserved in 17 other anchialine ponds on San Salvador Island.

Factors influencing the structure and spatial distribution of fishes in the headwater streams of the Jaú River in the Brazilian Amazon.

The aim of this study was to investigate the influence of spatial variation in river channels and habitats on the distribution of fish communities in the headwater streams of the Jaú River System, a blackwater tributary of the Negro River. Collections and measurements were made in 34 headwater streams during the period of November- December, 1998. Fish were captured with fish traps and hand nets along standard reaches of two meanders. Data on benthic habitat structure, stream depth and width were collected along lateral transects in each sample reach. A total of 66 fish species from 24 families were collected and classified into seven trophic guilds: allocthonous insectivore, autochthonous insectivore, general insectivore, piscivore, detritivorous planktivore, detritivorous insectivore and insectivorous piscivore. Variations in the distribution and diversity of bottom substrates were important factors influencing fish community structures in these systems. Also, variation in stream size explained the observed variability in fish communities.

Ichthyofauna of the Ribeirão Taboão, Paraíba do Sul river basin, Mogi das Cruzes, SP

We present herein a list of fish species from Ribeirao Taboao, a tributary of Rio Paraiba do Sul basin that is located in the metropolitan region of Sao Paulo. Fish were caught with trapezoid hand nets, mesh nets and fish traps. We sampled 145 specimens, belonging to 18 species, distributed in eight families and six orders. The most representative order was Characiformes, with six species, followed by Siluriformes with five species, Gymnotiformes with three species, Labriformes with two species, and Cyprinodontiformes and Synbranchiformes with a single species each. The four more abundant species were the livebearer Phalloceros reisi, the catfish Imparfinis piperatus, the cichlid Geophagus brasiliensis and the tetra Astyanax aff. fasciatus, which summed approximately 66% of the total sampled specimens. The 18 species of fish sampled in the present study correspond to almost 5% of the species registered for the Rio Paraiba do Sul drainage in the State of Sao Paulo, indicating a high diversity for a headwater stream. Endangered or introduced species were not found, but five species remain with indefinite taxonomical status.

Central clearing of OTC derivatives: Bilateral vs multilateral netting

Abstract We study the impact of central clearing of over-the-counter (OTC) transactions on counterparty exposures in a market with OTC transactions across several asset classes with heterogeneous characteristics. The impact of introducing a central counterparty (CCP) on expected interdealer exposure is determined by the tradeoff between multilateral netting across dealers on one hand and bilateral netting across asset classes on the other hand. We find this tradeoff to be sensitive to assumptions on heterogeneity of asset classes in terms of `riskyness' of the asset class as well as correlation of exposures across asset classes. In particular, while an analysis assuming independent, homogeneous exposures suggests that central clearing is efficient only if one has an unrealistically high number of participants, the opposite conclusion is reached if differences in riskyness and correlation across asset classes are realistically taken into account. We argue that empirically plausible specifications of model parameters lead to the conclusion that central clearing does reduce interdealer exposures: the gain from multilateral netting in a CCP overweighs the loss of netting across asset classes in bilateral netting agreements. When a CCP exists for interest rate derivatives, adding a CCP for credit derivatives is shown to decrease overall exposures. These findings are shown to be robust to the statistical assumptions of the model as well as the choice of risk measure used to quantify exposures.

Effectiveness of two sampling protocols to survey orchid bees (Hymenoptera: Apidae) in the Neotropics

We compared the performances of two different methodologies for collecting orchid bees (Hymenoptera: Apidae): active sampling (at chemical baits with hand nets) versus passive sampling (with baited traps). Data were retrieved from previous field studies in which both methodologies were employed simultaneously. We evaluated the effectiveness of each method in terms of the number of species collected and the composition of the bee species through paired t test and Permutational Multivariate Analysis of Variance, respectively. Active sampling collected significantly more bee species than passive sampling in all but one study. The composition of bee species collected by each of the two methods was also significantly different. Larger bees belonging to Eulaema and Eufriesea species tended to be more frequent in traps. In contrast, all Euglossa species presented comparatively higher relative frequencies with active sampling. We challenge previous assertions that both methodologies are equally effective and argue that insisting on the sole use of baited traps in orchid-bee inventories may result in retrieving strongly biased raw data which will eventually lead to incorrect conclusions about the actual composition of orchid-bee assemblages. Since orchid bees have been more and more used as key organisms in studies on environmental impact in the Neotropics, particularly in Brazil, and the passive sampling methodology has been adopted as the “official” one by the Brazilian environmental agency (IBAMA), we suggest a re-evaluation of this practice and the adoption of the more expensive, but more reliable, methodology of using well-trained field researchers to actively collect data on these important Neotropical pollinators.