Hand Nets Research Articles

A novel vehicle-mounted sticky trap; an effective sampling tool for savannah tsetse flies Glossina morsitans morsitans Westwood and Glossina morsitans centralis Machado.

Black screen fly round (BFR) is a mobile sampling method for Glossina morsitans. This technique relies on the ability of operator(s) to capture flies landing on the screen with hand nets. In this study, we aimed to evaluate a vehicle-mounted sticky panel trap (VST) that is independent of the operator's ability to capture flies against BFR, for effective and rapid sampling of G. m. morsitans Westwood and G. m. centralis Machado. We also determined the influence of the VST colour (all-blue, all-black or 1:1 blue-black), orientation and presence of odour attractants on tsetse catch. Using randomised block design experiments conducted in Zambia, we compared and modelled the number of tsetse flies caught in the treatment arms using negative binomial regression. There were no significant differences in the catch indices of the three colour designs and for in-line or transversely oriented panels for both subspecies (P > 0.05). When baited with butanone and 1-octen-3-ol, VST caught 1.38 (1.11-1.72; P < 0.01) times more G. m. centralis flies than the un-baited trap. Attractants did not significantly increase the VST catch index for G. m. morsitans (P > 0.05). Overall, the VST caught 2.42 (1.91-3.10; P < 0.001) and 2.60 (1.50-3.21; P < 0.001) times more G. m. centralis and G. m. morsitans respectively, than the BFR. The VST and BFR took 10 and 35 min respectively to cover a 1 km transect. The VST is several times more effective for sampling G. m. morsitans and G. m. centralis than the BFR and we recommend its use as an alternative sampling tool.

USING COLORED SHADE NETS AND ORGANIC MULCH TO IMPROVE MICROCLIMATE, GROWTH, AND YIELD OF YELLOW SWEET PEPPER

The study was carried out to investigate the effect of using color shade nets and organic mulch on improvement microclimate, growth, yield, and its components and fruit quality of yellow sweet pepper cv. Yellow Star F1 under high temperature. The study was conducted at El- Arish Agriculture Research Station, Agric. Res. Center, North Sinai Governorate, Egypt, during the summer seasons of 2018 and 2019. The results indicated that application of color shade nets modified microclimate around pepper plants where decreased average monthly of air temperature and light intensity; however, increased air relative humidity compared with unshaded. On the other hand, using black, green, and white shade nets combined with dry vegetable residues mulch followed by barley straw mulch reflected the lowest soil temperature at depths 10 and 20 cm in both growing seasons. Also, the results showed that using green shade nets followed by black shade nets combined with dry vegetable residues or barley straw mulches recorded the highest values for a fresh and dry weight of pepper plant organs. Besides, the highest contents of Chlorophyll b in leaves and vitamin C in fruit juice were obtained when covered by green nets combined with dry vegetable residues mulch in both seasons. Also, results revealed that the interaction between shading of yellow fruit pepper plants by black and green color nets with dry vegetable residues mulch significantly increase average fruit weight and total fruit yield for marketable yield compared to the open field without mulching in the first and second season. For that, it is recommended using of shade color nets (Black and green) with organic mulch (dry vegetable residues mulch and/or barley straw mulch) under high-temperature regions for modifying microclimate conditions of pepper plants and soil to improve growth, productivity, and fruit quality traits.

Digital record of specimens, including voucher material, from the study of a pollinator habitat restoration site under a commercial solar array in Jackson County, Oregon, 2019

Photovoltaic solar energy installation is booming, frequently near agricultural lands. Traditionally, the land underneath ground-mounted photovoltaic panels is unused, though some are repurposing it as habitat for pollinating insects. However, the impact of the solar panel canopy on the pollinator-plant community understory is unknown. In this study (Graham et al., 2020), we investigated the effects of solar arrays on plant composition, bloom timing and foraging behavior of pollinators in open fields (control), and in full shade and partial shade areas under solar panels in a predominant agricultural region of southern Oregon. Pollinating insect specimens were collected using hand nets, and identified to the lowest taxonomic group possible by M. Graham, A.R. Moldenke, and L.R. Best. A total of 85 voucher specimens were deposited into the Oregon State Arthropod Collection; accession record: OSAC_AC_2021_03_11_001-01.

Evaluation of four different methods for assessing bee diversity as ecological indicators of agro-ecosystems

Monitoring of wild bees is becoming more and more popular in nature conservation because of the high indicator value of this insect group. However, uncertainties about the sampling performance of different methods still exist, especially in areas of limited accessibility. We therefore compared four commonly applied sampling methods across vineyard fallows in a species diverse study area over two successive years: hand netting along variable transects (HN), pan traps (PT), trap nests (TN) and Malaise traps (MT). The chosen method significantly affects the number of sampled bee species and individuals, with PT sampling by far the largest number of species and individuals, and HN sampling the most diverse bee fauna. HN samples contained a significantly higher proportion of males, red-listed, large and social Bombus species than PT, but HN and PT samples contained a significantly lower proportion of male individuals compared to MT and TN. PT colour had a significant effect on the number of sampled individuals and species, with yellow PT sampling the largest numbers, while blue PT sampled the largest number of individuals of social Bombus species. The HN sampling results of an experienced and a less-experienced observer differed remarkably, with the turnover component of the Jaccard distance being significantly higher compared to the nestedness component. Our findings indicate that PT was the most efficient method for sampling bees in our study system. Due to species-specific differences in attractivity, sets of different PT colours should be used. However, if the study focus is on red-listed species or male individuals, HN represents a more efficient method. When HN is applied, observer bias should be considered as much as possible, especially with regard to differences in sampling experience. Due to different shortcomings, MT and TN cannot be seen as appropriate methods for standard monitoring of bees.

Assessment of ecto and endo parasites of Schizothorax plagiostomus inhabiting river Panjkora, Khyber Pakhtunkhwa, Pakistan.

Fish provides main source of high quality protein to more than one billion people in the world. Fish parasites directly affect the productivity of fish and indirectly on human health. This research was aimed to assess the helminth parasites in Schizothorax plagiostomus (the snow trout) from river Panjkora, KP, Pakistan. A total of 88 fish samples (n= 88) were collected from the upper, middle and lower regions of the river through cast nets, hand nets and hooks. All the collected fish samples were examined in the Parasitology Laboratory, Department of Zoology, University of Malakand for helminth parasites during July 2018 to February 2019.Among these fishes nematodes, trematodes, cestodes and acanthocephalan were isolated and identified. Overall prevalence of the fish parasites was 60.22% (53/88). The intensity of the parasite was observed from 1.7% to 4.61%. Highest prevalence was reported in summer season 86.36% while lowest in the winter season 36.36%. This study shows that summer season affects the fish business and result in poor quality fish meat with risk of zoonotic diseases. Adults were highly infected 82.25% while no infection was found in juvenile specimens. Female fish samples had higher prevalence 68.22% than males 48.22%. Fishes of the lower reaches had highest prevalence 60.22% than the upper reaches 40.0%. Fish samples with maximum length and weight were highly 76.92% infected than small sized fish with low body weight. Present study addresses that Rhabdochona schizothoracis in the intestine and Diplozoon paradoxum in gills of snow trout fish has a long term relationship and call as a natural infection in cyprinids and it is zoonotic threat to human.

FIRST RECORD OF EIGHT BRACHYURAN CRABS’ SPECIES (CRUSTACEA-DECAPODA) IN SOCOTRA ARCHIPELAGO IN THE INDIAN OCEAN-YEMEN

Yemen has a number of islands on the Red Sea, including Kamaran, Uqban, Hanish Archipelago Islands, Mayun (older name: Perim), and many islands at the Gulf of Aden, in the Indian Ocean, this also includes the Socotra Archipelago located 240 km from the east of the Horn of Africa and 380 km from Yemen. Socotra Island has a variety of habitats including sandy shores, rocky shores, mud flats, sponge areas, coral reefs, and freshwaters. This study aims to record the brachyuran crab’s species in different habitats in Socotra Archipelago. The specimens of the brachyuran crabs collected by hand, hand nets, and snorkeling up to 3-meter depth. The specimens were collected from 6 sites in Socotra Islands during separate periods time from 1984 to 2000, these specimens kept in Rostock University and Zoologische Staatssammlung München (ZSM)-Germany. In this present study, 32 brachyuran crabs’ species were recorded belonging to 11 superfamilies, 14 families, and 29 genera. Eight of these species represent the first records in Socotra Islands. The dominant brachyuran crab families in this region were Xanthidae, 35% with 11 species recorded, followed by Grapsidae, 19% with 6 species.

Notas sobre el uso de ecosistemas subterráneos por murciélagos en el Parque Nacional Tingo María, Huánuco, Perú

En el Perú existe poca información sobre la biodiversidad de los ecosistemas subterráneos, particularmente de las cuevas. En este trabajo registré qué especies de murciélagos habitan las cuevas del Parque Nacional Tingo María (PNTM) y cómo se distribuyen dentro de las mismas categorizándolas en tipos de percha. Evalué seis formaciones rocosas en el PNTM en los años 2015 y 2017. Se usaron redes de niebla y de mano para capturar a los murciélagos. En total registre 16 especies de murciélagos pertenecientes a las familias Phyllostomidae, Emballonuridae y Mormoopidae. En la cueva de “Las lechuzas” encontré el mayor número de especies (10). Categoricé tres tipos de percha usados por los murciélagos dentro de las cuevas: (I) pequeñas bóvedas formadas como depresiones en el techo, (II) espacios angostos en medio de las estalactitas, (III) cavidades amplias entre las estalactitas y la pared en forma de campana. Las cuevas del PNTM contribuyen a la persistencia local de los murciélagos proveyéndoles de refugios, y existe la necesidad de conocer sobre los aspectos ecológicos y la importancia funcional de los murciélagos dentro de estas cuevas.

Genetic characterisation of the intermediate hosts of schistosomiasis in its southern distribution limit in South America

ABSTRACT Schistosomiasis is a tropical disease caused by the digenean parasite Schistosoma mansoni. In South America it is transmitted to humans via freshwater snails of the genus Biomphalaria. In a global warming scenario, disease range expansions to subtropical countries are possible. For the first time, the distributions and genetic identification of Biomphalaria specimens in border regions of Uruguay are reported. The inclusion of Uruguayan samples allows a better understanding of the relationships between and within taxa of Biomphalaria. Samples were collected between 2015 and 2016 using hand nets. Initially, they were classified morphologically. They were then classified genetically by analysing a fragment of the cytochrome c oxidase subunit I gene. Phylogenetic analysis revealed the presence of B. peregrina and B. occidentalis. Species belonging to the B. tenagophila complex were also recognised. Individuals initially identified from their external morphology as B. tenagophila tenagophila showed inconsistencies with the analysis of COI sequences that assigned them to B. occidentalis. Since the presence of schistosomiasis in Uruguay is likely to occur in the next few years, an exhaustive population survey of Biomphalaria taxa should be urgently developed to identify the presence of S. mansoni and the places most susceptible to be colonised by these snails.

Ichthyofaunal diversity and physiochemical parameters of Gandiali Dam Kohat, Khyber Pakhtunkhwa, Pakistan

Our research focuses on the biodiversity of fishes in the Gandiali Dam in the district of Kohat. With the assistance of local fishermen, all 20 fish specimens were taken from Gandiali Dam in the district of Kohat, Khyber Pakhtunkhwa. From February to August 2022, he used various nets, including hand nets, cast nets, and hooks. Small live fishes (up to 15 centimetres) have been transferred directly to formalin and died at the scene (mix of 1 part formalin and 9x water or 10 milliliter formalin and 90 milliliter water), while big live fishes have been transferred to the solution that died instantly (mix of 1 part formalin and 9x water or 10 milliliter formalin and 90 milliliter water), After a few minutes, the deaths happened in this solution, and at the time of death, all of the fins expanded, allowing the number of fin rays, etc., to be counted, making verification of many species simple. A thin incision is made on the abdomen to preserve large specimens (15 to about 30 cm or above), and concentrated formalin was infused at many body regions along the abdominal region. Thus every fish sample was then identified to the species level. The species were identified based on their primary colours, particular spots or signs on the body surface, body shape, structure of various fins, and so on. A total of 7 species were reported during the sampling period, which belonged to two orders (Cypriniformes and Channiformes), two families (Cyprinidae and Channidae) and seven genuera. Family Cyprinidae is the most richest family having 6 species (19 samples) viz Cyprinus carpio, Labeo rohita, Ctenopharyngodon idella, Hypophathalmichthys molitrix, Carassius auratus and Puntius ticto. Family Channidae was represented by Channa punctatus (1 sample). During the sampling period, most abundant specie reported was Cyprinus carpio (08 samples) followed by Labeo rohita. The present study concludes with a note that the water bodies of Gandiali dam District Kohat, Khyber Pakhtunkhwa are home to rich and diverse fauna of cyprinids, and cyprinids have successfully adapted themselves to the haline water of the area. Further studies are required to evaluate the mechanism which enables those freshwater fishes survive and thrive in such extreme haline environment.

Diversity of butterflies in different habitat types of Seethawaka wet zone botanic gardens and Indikadamukalana forest reserve of Sri Lanka

Botanic gardens, forest reserves and other protected areas are established to conserve biodiversity. The present study was conducted to assess the butterfly diversity in a recently established botanic garden of Sri Lanka, the Seethawaka Wet Zone Botanic Gardens (SWZBG) and Indikadamukalana Forest Reserve (IMFR) adjacent to the garden. Three different habitat types within the botanic gardens, the undisturbed forest habitat within the forest reserve and the buffer zone between the Botanic Gardens and Forest Reserve were investigated for butterflies. Butterfly species richness, diversity, endemic species, family composition in different habitats and effects of habitat parameters on butterfly distribution were assessed. Butterflies were collected from five habitats – grassland, shrub, disturbed forest, undisturbed forest, buffer zone, of the SWZBG and IMFR using transect line method with hand netting and fruit baited traps. Collected butterflies were identified using published field guides. Climate and soil parameters of each habitat were measured using standard methods and equipment. Differences of habitat parameters between habitats were estimated using One-Way Analysis of Variance and Tukey’s Multiple Comparison method and butterfly diversity and evenness in different habitat types were assessed using Shannon-Weiner diversity index. The study revealed seventy-nine butterfly species from SWZBG and IMFR highlighting the importance of the sites for safeguarding and conservation of butterflies. Species richness and diversity of butterflies was highest in the buffer zone and lowest in the grassland habitat. The most common butterfly family in the study sites was family Nymphalidae. Endemic species were high in the forest habitat types. Significant differences were evident in habitat parameters between habitat types indicating their effect on butterfly species richness and diversity. The study revealed SWZBG and IMFR as important areas for butterfly occurrence when compared with similar botanic gardens and forest reserves elsewhere in the world.

Impacts of trace metals on African common toad, Amietophrynus regularis (Reuss, 1833) and depuration effects of the toad's enteric parasite, Amplicaecum africanum (Taylor, 1924) sampled within Lagos metropolis, Nigeria

The study aimed at assessing the depuration potentials of endoparasite, Amplicaecum africanum on trace metals in its toad host, Amietophrynus regularis at sites of significant anthropogenic perturbations within the Lagos metropolis, in Nigeria. A total of 120 toads of both sexes, alongside 45 soil samples were collected from each of three (3) stations labeled Dumpsite, Lagoon front and Highrise, using hand nets and by hand-picking between February and October, 2018. The intestinal tissues sections of the toads were examined using a binocular dissecting microscope (American Optical Corporation, Model 570) and hematoxylin and eosin (H&E) stain. Oxidative stress in toad intestine was assessed by estimating the levels of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (MDA). Trace metals in the water, soil, toad liver, intestine and parasite, Amplicaecum africanum were tested using Atomic Absorption Spectrophotometry (Philips model PU 9100). Lead (Pb), copper (Cu), nickel (Ni), cadmium (Cd), and chromium (Cr) were detected in the toads, with the infected toads having lower concentrations of most trace metals than the uninfected toads, irrespective of the locations and sex. Strong negative correlations between parasitological indices and concentrations of trace metals in the toads suggest that the parasites might have taken up significant amounts of trace metals from the host. The study demonstrated the potentials of parasite, A. africanum to depurate trace metal burden in Amietophrynus regularis. When the dominant factor impacting the toad is the parasitic infection, parasite intensity determines the trade-off between parasitological harm and depuration benefit to the host. Hence, under controlled conditions, parasites may serve as bioremediation agent in the event of pollution. Depuration potential of A. africanum in the study was supported by the mild tissue alterations observed in the intestine of infected toads, compared to the uninfected counterparts, which exhibited severe glandular hyperplasia, increased connective tissue, and severely stunted villi. Consistently lower activities of biochemical biomarkers which characterize the uninfected toads compared to the infected, irrespective of the sex and stations, further corroborate drawn inferences.

The Psilotreta Banks, 1899 of the Dabie Mountains, east central China, with descriptions of two new species (Insecta: Trichoptera: Odontoceridae)

The authors collected caddisflies in the Dabie Mountains in 2014 and 2015. Three species of Psilotreta Banks, 1899 were found: Psilotreta daidalos Malicky, 2000, P. furcata sp. nov., and P. brevispinosa sp. nov. The species were collected by light sheet traps or hand nets near streams in mountainous forests. All the species are described and illustrated, and the species groups to which they belong are discussed. Some variation within P. daidalos is described and the species is newly recorded from the Anhui and Hubei Provinces.

Influence of hand net mesh type and sex on experimental infection with Aeromonas hydrophila in Brazilian native fish Astyanax altiparanae

Farmed fish are permanently exposed to management procedures such as netting that can result in stress, skin injuries and subsequent secondary infections. The type of mesh material can modulate the magnitude of netting injury, yet there is scarce information on this topic for aquaculture species. The aim of this study was to evaluate the influence of net material on experimental infection by Aeromonas hydrophila using male and female Astyanax altiparanae, yellowtail tetra, as an infection model. Two hundred and fifty six A. altiparanae were distributed into 16 groups considering sex, types of net material (nylon, polypropylene, polyethylene, and a control group handled without net), and immersion challenge with A. hydrophila. Prior to infection, fish were anesthetized and submitted to netting for 30 s. Immediately, a fluorescein bath was applied under UV light to detect skin lesions. Later, fish were infected by immersion challenge in diluted bacterial solution, while control groups were immersed in sterile PBS. It was verified that the fish handled with nylon net mesh showed more extensive lesions than groups handled with polypropylene and polyethylene nets. Survival after infection was significantly lower in fish previously handled with nylon net when compared to all other groups, while no differences were found between polypropylene, polyethylene nets or fish handled by hand. There was no gender influence on lesions or mortality. It was concluded that yellowtail tetra is sensitive to netting and polypropylene and polyethylene capture nets should be used for handling this species. Additionally, nylon hand nets should be banned to avoid injuries that could serve as gateways for opportunist pathogens such as A. hydrophila

CHARACTERIZATION OF THE BIOTIC (MACROPHYTES AND MACROINVERTEBRATES) AND ABIOTIC FACTORS OF PANTANAL PONDS IN THE MIRANDA RIVER FLOODPLAIN

The Pantanal has an exuberant biodiversity that is constantly regulated by the dynamics of the climate and by the flood pulses. The objective of this work was to characterize and evaluate the biotic (macrophytes and macroinvertebrates) and abiotic factors (pH, temperature, dissolved oxygen, conductivity, total dissolved solids, water turbidity, chlorophyll a and pheophytin-a) of Pantanal ponds depending on the dry or rainy season. Therefore, five ponds with different characteristics were analyzed and five samples of water were collected during the dry and rainy season. For sampling of the macrophytes and collection of the macroinvertebrates we used hand nets (area of 0,09m2, opening of 5000 μm). This was done in order to observe seasonal difference in pH, chlorophyll-a and pheophytin-a and spatial differences between dissolved oxygen, electrical conductivity, turbidity, chlorophyll a and pheophytin-a was observed. The aquatic macrophyte Eichornia azurea ( Commelinales, Ponteridaceae) showed high dominance and relative vegetation cover in at least three ponds, which was also related to higher values of macroinvertebrate biomass. On the other hand, the ponds that presented low dominance or absence of E. azurea presented high diversity of aquatic macrophytes. However, these intrinsic biological characteristics of the ponds altogether with the abiotic parameters demonstrated that there are distinct patterns in the dynamics of these ecosystems during the drought and flood regimes.

Molecular Detection of Rickettsia felis and Rickettsia bellii in Mosquitoes.

To add to the limited information on Rickettsia in mosquitoes in China, we carried out a PCR survey on convenience samples of 3051 mosquitoes collected with hand nets in and around domestic dwellings in 25 provinces. Five species of mosquitoes were identified: Culex pipiens pallens (n = 1620), Aedes albopictus (806), Armigeres subalbatus (377), Anopheles sinensis (168), and Culex tritaeniorhynchus (80). A Rickettsia nested-PCR targeting the variable domain of gltA showed Rickettsia felis in four mosquito species of 16 provinces Cx. pipiens pallens (1.8%, 29/1620); Ae. albopictus (1.2%, 10/806); An. sinensis (1.2%, 2/168); and Ar. subalbatus (2.1%, 8/377). Rickettsia bellii was also widespread, occurring in 12 provinces and 2 species: Cx. pipiens pallens (4.3%, 69/1620) and An. sinensis (0.6%, 1/168). R. felis and R. bellii were found in almost similar numbers in female [1.5% (27/1809) and 1.2% (21/1809), respectively] as in male mosquitoes [1.8% (22/1242) and 4.0% (49/1242), respectively]. Our results indicated that mosquitoes in China are widely infected with R. felis, the agent of human flea-borne spotted fever, and that R. bellii can also occur outside of the Americas and its usual tick hosts.

Providing biodiversity information to support sustainable development of Sugihan wetlands, South Sumatra

Air Sugihan or Sugihan wetlands is a subdistrict in Ogan Komering Ilir district, South Sumatra province, Indonesia. The area covering is about 2.593 km2, mostly dominated by wetlands, ranging from peatland to the mangrove zone. The Padang-Sugihan Wildlife Reserve is a Wildlife Sanctuary that borderly or within Air Sugihan wetlands. Before the area was set aside for a wetland reserve in April 1983 the area was being prepared for transmigrant settlers. Among other threatened wildlife, birds and fishes are two taxa that very fragile to human disturbances. Since November 2016, we explore basic biodiversity information of Sugihan wetlands, particularly focus on fish and bird diversity. A total of 33 species of fishes and 39 birds were recorded, suggest the wetlands in this area support important habitat of rich diversity. To collect information on bird diversity, three survey methods were applied (riverine survey, time point counts and incidental search). For collecting data of fishes, we collect specimens from local fishermen, with additional data collected by us using hand netting and fish trap netting. Long-term study was initiate to providing comprehensive biodiversity information to support sustainable development of Sugihan wetlands.

Biogeographic differentiation between two morphotypes of the Southern Ocean diatom Fragilariopsis kerguelensis

Fragilariopsiskerguelensis (O’ Meara) Hust. is a ubiquitous diatom of the Southern Ocean. Its thick frustules are the numerically dominant component of the siliceous sediment layer covering large parts of the seafloor beneath. Morphometric variability of frustules of this diatom has been of interest for paleoenvironmental reconstructions. Recently, two morphotypes differentiated by the morphometric descriptor rectangularity were described from a Southern Ocean sediment core, the relative abundance of which correlated with reconstructed paleotemperatures. In the present study, we use semi-automated microscopic and image analysis methods to answer whether these morphotypes also appear in recent assemblages, and if yes, do their distributions reflect geographic location or environmental factors. Three transects from the water column, sampled along the Greenwich meridian with hand nets, and one sediment surface transect from the South Pacific, were analyzed. In each of these transects, both morphotypes were detected, and annual mean sea surface temperatures (SST) were found to be a good predictor of their relative abundances. The transition between dominance of one or the other morphotype appeared roughly between the Antarctic Polar Front and the Southern Boundary of the Antarctic Circumpolar Current. Although more extensive circumpolar sampling will be needed to confirm the generality of our conclusions, the observed morphometric cline is a novel aspect of the biology of this species and can in the future potentially be used for further developing paleoproxies especially for highly F.kerguelensis-dominated sediment in the Southern Ocean.

Length–weight relationships of eight fish species from Guyana coastal drainages, Amapá, Brazil

The present study provides the length–weight relationships (LWR) for eight fish species in 19 streams from the Pedreira River basin, a small tributary of the Guyana coastal drainages from Amapá State, Brazil. Fishes were collected at two occasions, one in November 2016, the other in July 2018, using hand nets, with 0.5 mm of mesh size and 0.25 m2 of mouth area, and trawl nets, with 0.5 mm of mesh size and 3 m long. Standard length and total weight were measured to determine the LWRs. The results show that the coefficient b varied between 2.798 and 3.380 and thus the values were within the expected range.

Length–weight relationship for freshwater fish species from Brazilian Cerrado

Presented are length–weight relationship (LWR) estimates for 15 native fish species captured between 2010 and 2011, in the Munim River, Brazilian Cerrado basin. Samples were collected using gillnets of four different mesh sizes (3.0, 4.0, 5.0 and 6.0 cm), hand nets and a covo-fish trap. Additionally provided are the first LWRs for eight species, specially the recently described species Charax awa Guimarães, Brito, Ferreira & Ottoni, 2018.

Length–weight relationships of 11 fish species from streams of Anapu River Basin, State of Pará, eastern Amazon, Brazil

The present study shows the length–weight relationships (LWR) for 11 stream fish species from Anapu River Basin, in eastern Amazon, Pará State, Brazil. Samplings were carried out in October and November 2010, 2012 and 2013, and fishes were collected using hand nets of 55 cm of diameter and 2 mm mesh size. Fixed specimens were measured for standard length (cm) and total weight (g). Allometric coefficients b varied from 2.606 to 3.335 and coefficients of determination (R2) varied from 0.902 to 0.986. Shrinkage effect must be considered in future investigations in order to provide a correction factor.