One more step in solving the Chydorus puzzlea morphological comparison between Chydorus tilhoi Rey & Saint-Jeans, 1969 and Chydorus sphaericus (O.F. Mller, 1776) (Crustacea: Cladocera).

A number of species of Chydorus Leach, 1816 (Crustacea: Cladocera) need improvements in their taxonomy much more than any other genus within the family Chydoridae Dybowsky & Grochowski, 1894 emend. Frey, 1967, which makes the systematics of the genus still a puzzle that lacks several pieces. Here, we redescribe the African species Chydorus tilhoi Rey & Saint-Jeans, 1969 and compare its morphology with that of Chydorus sphaericus (O.F. Mller, 1776). The two taxa might be easily differentiated because C. tilhoi has a single and relatively large major head pore with a wide rim, labral keel elongated with a large spine, and postabdomen with postanal part elongated, narrowing distally and with denticles near its anal margin, organized in groups. These morphological traits are absent in C. sphaericus. Chydorus tilhoi and C. sphaericus also differ in the morphology of the first (Inner Distal Lobe setae), third (exopodite proportion), and fifth (exopodite shape) limbs. Based on the literature and our observations, the limb morphology of C. tilhoi has important similarities with that of C. breviceps, C. nitidulus and C. dentifer, and their translocation to a new genus seems to be a fundamental piece in the puzzle of Chydorus.

New records of Coronatella (Crustacea, Branchiopoda, Chydoridae) from Colombia with the first report of Coronatella undata and of the male of Coronatella monacantha

Abstract Biological samples obtained from a small temporary pond of northern Colombia yielded the first record Coronatella undata Sousa, Elmoor-Loureiro and Santos, 2015 and of the male of C. monacantha (Sars, 1901) for Colombia. In this study, the morphology of female of Coronatella undata and female and male of C. monacantha was described and compared to other species within the genus. C. undata was originally described from Brazil and, among the species of the Coronatella monacantha complex, seems to be closely related to C. acuticostata (Sars, 1903). C. undata shows some similarities with C. monacantha, but it can be identified by important diagnostic characters such as: 1) posterior-ventral corner of valve with two denticles, 2) seta on exopodite of trunk limb II rudimentary, 3) filter comb of trunk limb II with six setae, 4) ODL seta of trunk limb I shorter than longest seta of IDL. C. monacantha is the most reported species in the Neotropical region and the male most resemble C. paulinae Sousa, Elmoor-Loureiro & Santos, 2015 in relation to (i), length/wide of postabdomen ratio (ii) basal spine almost straight and (iii)) long basal spine reaching the mid-length of basal spine. However, they can be separated by (i) number of lateral seta on the antennule, (ii) postanal angle, (iii) position of gonopore (iv) presence of a denticle on posterior-ventral corner of valve

Resumo Amostras biológicas obtidas de uma pequena lagoa temporária do norte da Colômbia proporcionaram o primeiro registro de Coronatella undata Sousa, Elmoor-Loureiro e Santos, 2015 e do macho de Coronatella monacantha (Sars, 1901) na Colômbia. Neste estudo, foi descrita a morfologia de fêmeas de C. undata e de fêmeas e machos de C. monacantha, comparando-a com outras espécies do gênero. Coronatella undata foi descrita originalmente no Brasil e, entre as espécies do complexo C. monacantha, parece estar intimamente relacionada com Coronatella acuticostata (Sars, 1903). Coronatella undata apresenta algumas semelhanças com C. monacantha, mas pode ser identificada por seus principais caracteres, tais como: 1) ângulo posterior ventral da valva com dois dentículos; 2) cerda rudimentar no exopodito do ramo do tronco II; 3) filtro da gnatobase do apêndice torácico II com seis cerdas; 4) cerda ODL do membro do tronco I mais curta que a cerda mais longa do IDL. Coronatella monacantha é a espécie mais relatada na região neotropical, e o macho se assemelha mais a Coronatella paulinae Sousa, Elmoor-Loureiro & Santos em relação à/ao: (i) razão comprimento / largura do pós-abdômen, (ii) espinho basal quase reto e (iii) espinho basal longo com a metade do comprimento do espinho basal. No entanto, eles podem ser separados pelo/pela: (i) número de cerdas laterais na antênula, (ii) ângulo postanal, (iii) posição do gonóporo e (iv) presença de dentículo no canto ventral posterior da valva.

New records of Coronatella (Crustacea, Branchiopoda, Chydoridae) from Colombia with the first report of Coronatella undata and of the male of Coronatella monacantha / Novos registros de Coronatella (Crustacea, Branchiopoda, Chydoridae) na Colômbia com o primeiro relato de Coronatella undata e o macho de Coronatella monacantha

Biological samples obtained from a small temporary pond of northern Colombia yielded the first record Coronatella undata Sousa, Elmoor-Loureiro and Santos, 2015 and of the male of C. monacantha (Sars, 1901) for Colombia. In this study, the morphology of female of Coronatella undata and female and male of C. monacantha was described and compared to other species within the genus. C. undata was originally described from Brazil and, among the species of the Coronatella monacantha complex, seems to be closely related to C. acuticostata (Sars, 1903). C. undata shows some similarities with C. monacantha, but it can be identified by important diagnostic characters such as: 1) posterior-ventral corner of valve with two denticles, 2) seta on exopodite of trunk limb II rudimentary, 3) filter comb of trunk limb II with six setae, 4) ODL seta of trunk limb I shorter than longest seta of IDL. C. monacantha is the most reported species in the Neotropical region and the male most resemble C. paulinae Sousa, Elmoor-Loureiro & Santos, 2015 in relation to (i), length/wide of postabdomen ratio (ii) basal spine almost straight and (iii)) long basal spine reaching the mid-length of basal spine. However, they can be separated by (i) number of lateral seta on the antennule, (ii) postanal angle, (iii) position of gonopore (iv) presence of a denticle on posterior-ventral corner of valve.

Amostras biológicas obtidas de uma pequena lagoa temporária do norte da Colômbia proporcionaram o primeiro registro de Coronatella undata Sousa, Elmoor-Loureiro e Santos, 2015 e do macho de Coronatella monacantha (Sars, 1901) na Colômbia. Neste estudo, foi descrita a morfologia de fêmeas de C. undata e de fêmeas e machos de C. monacantha, comparando-a com outras espécies do gênero. Coronatella undata foi descrita originalmente no Brasil e, entre as espécies do complexo C. monacantha, parece estar intimamente relacionada com Coronatella acuticostata (Sars, 1903). Coronatella undata apresenta algumas semelhanças com C. monacantha, mas pode ser identificada por seus principais caracteres, tais como: 1) ângulo posterior ventral da valva com dois dentículos; 2) cerda rudimentar no exopodito do ramo do tronco II; 3) filtro da gnatobase do apêndice torácico II com seis cerdas; 4) cerda ODL do membro do tronco I mais curta que a cerda mais longa do IDL. Coronatella monacantha é a espécie mais relatada na região neotropical, e o macho se assemelha mais a Coronatella paulinae Sousa, Elmoor-Loureiro & Santos em relação à/ao: (i) razão comprimento / largura do pós-abdômen, (ii) espinho basal quase reto e (iii) espinho basal longo com a metade do comprimento do espinho basal. No entanto, eles podem ser separados pelo/pela: (i) número de cerdas laterais na antênula, (ii) ângulo postanal, (iii) posição do gonóporo e (iv) presença de dentículo no canto ventral posterior da valva.

Revision of the guttata-group of Alona s. lato leads to its translocation to Prendalona Sousa, Elmoor-Loureiro & Santos, 2018 (Cladocera: Anomopoda: Chydoridae).

Revision of the guttata-group of Alona s. lato justifies its translocation to the genus Prendalona Sousa, Elmoor-Loureiro & Santos, 2018. Emended diagnosis of the genus and diagnoses for all its species are provided. Prendalona belong to the Hexalona-clade of Alona s. lato, it is a sister-group of genus Flavalona Sinev & Dumont, 2016, but differs from the latter in: (1) minute lateral head pores without any pockets below, (2) absence of the genital process on male postabdomen, and (3) absence of inner setae on endites 1-2 of thoracic limb I. Morphology of North American P. barbulata (Megard, 1967) and widely distributed P. guttata (Sars, 1862) is investigated in detail for the first time. Prendalona julietae sp. nov.,sibling-species of P. guttata, is described from Brazil. Global diversity and distribution patterns of Prendalona are discussed.

Contribution to the knowledge of cladocerans fauna (Crustacea, Branchiopoda) from La Española lagoon, Colombia

Thirty-five cladocerans species are recorded from La Española lagoon in the Orinoquia region of Colombia; all are new records for Meta Department and 10 for Colombia. With the addition of these new reports, the total number of cladocerans for Colombia and the Meta department is increased by 124 and 38 species, respectively. The cladoceran fauna from the surveyed area is represented mainly by widespread species, commonly found in the Neotropical regions, but local morphological data are scarce in the regional literature. Brief diagnostic description of 18 species of cladoceran fauna recorded of the Meta department-Colombia are provided together with illustrations of taxonomically significant appendages, morphological remarks, notes on the variability of some species, and their distribution.

Se registran treinta y cinco especies de cladóceros de la laguna La Española en la región de la Orinoquia de Colombia; todos ellos son nuevos registros para el Departamento del Meta y 10 para Colombia. Con la incorporación de estos nuevos reportes, el número total de cladóceros para Colombia y el departamento del Meta se incrementa en 124 y 38 especies respectivamente. La fauna de cladóceros del área estudiada está representada principalmente por especies de amplia distribución y que se encuentran comúnmente en las regiones Neotropicales, pero los datos morfológicos locales son escasos en la literatura regional. Se proporcionan breves descripciones diagnosticas de 18 especies registradas para la fauna de cladóceros del departamento del Meta-Colombia, junto con ilustraciones de apéndices taxonómicamente significativos, comentarios morfológicos, notas sobre la variabilidad de algunas especies y su distribución.

Contribución al conocimiento de Cladóceros de las charcas temporales al norte de Colombia / Contribution to knowledge of Cladocerans of temporary ponds to northern Colombia

Resumen Cuarenta y un taxones de Cladóceros fueron identificados en las charcas temporales en el curso de este estudio, de los cuales 15 son nuevos registros para el departamento de la Guajira y uno para Colombia. Con la adición de estos nuevos reportes se incrementa el total de cladóceras para Colombia y el departamento de La Guajira en 111 y 46 especies respectivamente. El departamento de La Guajira contiene el 41.44% de los taxones de cladóceros del territorio colombiano. Las charcas con mayor y menor riqueza fue la Ponderosa y la de Manaure con 37 y 2 especies respectivamente. También se proporcionan notas descriptivas, comentarios comparativos sobre morfología e ilustraciones para algunos taxones notables.

Abstract Forty-one Cladocera taxa were identified in temporary ponds during this study, of which 15 are new records for the department of La Guajira and one for Colombia. With the addition of these new reports, the total number of cladocerans for Colombia and La Guajira department is increased by 111 and 46 species respectively. La Guajira department comprises the 41.44 % of cladocera taxa of the Colombian territory. The pond with the greatest and lowest richness was Ponderosa and Manaure with 37 and 2 species respectively. Descriptive notes, comparative comments on morphology, and illustrations are also provided for some notable taxa.

New records of Coronatella (Crustacea, Branchiopoda, Chydoridae) from Colombia with the first report of Coronatella undata and of the male of Coronatella monacantha.

Biological samples obtained from a small temporary pond of northern Colombia yielded the first record Coronatella undata Sousa, Elmoor-Loureiro and Santos, 2015 and of the male of C. monacantha (Sars, 1901) for Colombia. In this study, the morphology of female of Coronatella undata and female and male of C. monacantha was described and compared to other species within the genus. C. undata was originally described from Brazil and, among the species of the Coronatella monacantha complex, seems to be closely related to C. acuticostata (Sars, 1903). C. undata shows some similarities with C. monacantha, but it can be identified by important diagnostic characters such as: 1) posterior-ventral corner of valve with two denticles, 2) seta on exopodite of trunk limb II rudimentary, 3) filter comb of trunk limb II with six setae, 4) ODL seta of trunk limb I shorter than longest seta of IDL. C. monacantha is the most reported species in the Neotropical region and the male most resemble C. paulinae Sousa, Elmoor-Loureiro & Santos, 2015 in relation to (i), length/wide of postabdomen ratio (ii) basal spine almost straight and (iii)) long basal spine reaching the mid-length of basal spine. However, they can be separated by (i) number of lateral seta on the antennule, (ii) postanal angle, (iii) position of gonopore (iv) presence of a denticle on posterior-ventral corner of valve.

Climate change and niche unfilling tend to favor range expansion of Moina macrocopa Straus 1820, a potentially invasive cladoceran in temporary waters.

Non-native species' introductions have increased in the last decades primarily due to anthropogenic causes such as climate change and globalization of trade. Moina macrocopa, a stress-tolerant cladoceran widely used in bioassays and aquaculture, is spreading in temporary and semi-temporary natural ponds outside its natural range. Here, we characterize the variations in the climatic niche of M. macrocopa during its invasions outside the native Palearctic range following introduction into the American continent. Specifically, we examined to what extent the climatic responses of this species have diverged from those characteristics for its native range. We also made predictions for its potential distribution under current and future scenarios. We found that the environmental space occupied by this species in its native and introduced distribution areas shares more characteristics than randomly expected. However, the introduced niche has a high degree of unfilling when displacing its original space towards the extension to drier and hotter conditions. Accordingly, M. macrocopa can invade new areas where it has not yet been recorded in response to warming temperatures and decreasing winter precipitation. In particular, temporary ponds are more vulnerable environments where climatic and environmental stresses may also lower biotic resistance. Supplementary Information: The online version contains supplementary material available at 10.1007/s10750-022-04835-7.

Richness and composition of Cladocera (Crustacea: Branchiopoda) in Brazilian rupestrian cerrados, with comments on distribution and taxonomy.

Several studies that involve a faunal survey of Cladocera in Brazil have been carried out in recent years; however, knowledge of the distribution and diversity of species of this group in semiterrestrial and aquatic bodies of rupestrian cerrado is still rare. The present study evaluated the richness and composition of cladoceran species in these environments in the central parts of the country. Samples were collected at nine sites of rupestrian cerrado from 2011 to 2012. In total, 47 cladocerans species were identified, belonging to six families, emphasizing the Chydoridae family with the greatest richness (32 species) and abundance. The species Bryospilus repens had its first record for the state of Goiás and the Brazilian Midwest. Other species were also recorded for the first time: Leberis davidi for the state of Minas Gerais, and Alona yara and Flavalona asymmetrica for the state of Bahia. This demonstrates that rupestrian cerrados are relevant for cladoceran diversity on a regional scale. Carrying out new inventories of cladocerans in similar phytophysiognomies could contribute significantly to the knowledge of the biodiversity of these animals in Brazil, in addition to providing updates on the geographic distribution of species already recorded in previous studies.

Identification key of Ctenopoda (Cladocera, Holopedidae, Sididae) taxa from Brazil with remarks on taxonomy and geographic distribution.

Using literature and field sampling data, we found that Brazilian fauna of the order Ctenopoda (Cladocera, Branchiopoda) was composed of twelve species, including the locally endemic Holopedium amazonicum and Sarsilantona behningi. In Brazil, Diapahanosoma (Neodiaphanosoma) bergamini was reported out of its type locality for the first time. Ctenopoda species were reported in all Hydrographic Regions in Brazil, however, the sampling effort was clearly distinct between many areas. These findings suggest the necessity of new faunal surveys in several parts of Brazil.

First record of Scapholeberis freyi Dumont and Pensaert, 1983 (Crustacea:Anomopoda: Daphniidae) from Colombia / Primer registro de Scapholeberis freyi Dumont and Pensaert, 1983 (Crustacea:Anomopoda: Daphniidae) en Colombia

Abstract From the analysis of plankton samples from a temporary pond of northern Colombia some female specimen of the daphinid cladoceran Scapholeberis freyi Dumont and Pensaert, 1983 was collected. It represents the first report in Colombia and expands its known occurrence in South America. The specimens observed are described and compared with available morphological data of their closest congeners. A brief descriptions of this taxon based on Colombian material is given.

Resumen A partir del análisis de las muestras de plancton de una charca temporal al noreste de Colombia algunos especímenes hembra del cladócero daphnido Scapholeberis freyi Dumont and Pensaert, 1983 fueron colectados. Este representa el primer reporte en Colombia y expande su rango distribucional conocido en Sur América. Los especímenes observados se describen y se comparan con los datos morfológicos disponibles de sus congéneres más cercanos. Una descripción breve de este taxón basado en el material colombiano es dada.

Richness and composition of the Cladocera community (Crustacea: Branchiopoda) from the Maranho State, Northeast Brazil.

The state of Maranho, northeast Brazil, has four different biomes. The water bodies in Maranho belongs to three hydrographic regions. Thus, the state potentially contributes to a high biodiversity. Despite that, in the state, the study of cladocerans can still be considered incipient. This work aims to summarize the list of species of cladocerans in the state of Maranho, including the results of new fauna surveys. We report ten new species records for the state, two species represent the new record of the genus Pseudosida Herrick, 1884. The results found point to the occurrence of 82 valid taxa in the state of Maranho.

More than just the number of denticles: morphometric and limb variability in Neotropical cladoceran Alonella dadayi (Crustacea: Cladocera: Chydoridae).

The aim of this study is to describe the limb morphology of Alonella dadayi Birge (Cladocera: Chydorida) and this species' morphometric variability regarding the carapace and postabdomen. We report for the first time a population whose individuals do not have denticles on the posteroventral corner of the carapace. Although we have observed intra- and interpopulation variability of the limbs (especially the proportion of Inner Distal Lobe setae), Alonella dadayi can also be differentiated from closely related species by the morphology of the exopodite of the second limb. The morphometric analyses show high variability in the shape of the carapace, when regarding the ventral margin and posterodorsal corner. In the postabdomen, we observed a significant variation in the preanal, anal and postanal margins. Keeping in mind the wide range of the geographic distribution of Alonella dadayi and its high morphological variability, it is possible that this taxon comprises a species complex. Such a chance needs to be tested in future studies.

Cladocera from the Upper Xingu River Basin with the description of a new genus of the Chydoridae (Crustacea: Branchiopoda: Anomopoda).

In this study, we investigated cladocerans (Crustacea: Branchiopoda) collected in six water bodies from the Upper Xingu River Basin, Central Brazil. In total, we found eighteen species belonging to three families. Furthermore, we also describe a new and highly specialized genus of Chydoridae. Kisakiellus aweti gen. nov., sp. nov. which shares some morphological traits with members of Chydorinae, particularly the exopodite of the fourth limb armed with seven setae. The new genus bears several autapomorphies and does not exhibit any clear affinities with any other genus of the subfamily. Apparently, K. aweti gen. nov., sp. nov. has a positive rheotactic behavior and the morphological characters related to this habitat trait are discussed. Many regions of the Upper Xingu River Basin are still in need of faunal inventories, a fact that gains more relevance due to the high potential for cryptic biodiversity. So, it is possible that an increase on the sampling effort in this basin will have a positive impact on the known diversity of Cladocera.

The amazing diversity of the genus Monospilus Sars, 1862 (Crustacea: Branchiopoda: Aloninae) in South America.

The main goal of this paper is to describe three new species of the genus Monospilus Sars, 1862 (Crustacea: Cladocera). Monospilus macroerosus sp. nov. differs from other species of the genus in several peculiar morphological traits, the most striking being the presence of a saw-shaped pecten of teeth on the postabdominal claw. This species inhabits semiterrestrial habitats (wet leaf litter on hydromorphic soil from gallery forest), exhibiting adaptations related to movement and food handling in this type of habitat. Monospilus brachyspinus sp. nov. inhabits truly aquatic habitats, where lives being associated with macrophytes and submerged leaves. It may be recognized by the postabdominal claw, which is armed with proximal spinulae modified in a short spine. In Monospilus sp., the proximal spinulae are modified in a long and slender spine. So far, Monospilus sp. occurs in southern South America, while Monospilus macroerosus sp. nov. and Monospilus brachyspinus sp. nov. occur in the Cerrado biome in Brazil, in the central portion of South America. Some conclusions about the conservation status of new species also are made.

Description of a new species of the costata-group (Cladocera, Chydoridae, Aloninae) from Brazil.

The aim of this study is to describe a new species of the costata-group from Brazil. Alona margipluma sp. nov. shares morphological traits with A. costata Sars, 1862, A. natalensis Sinev, 2008, and A. cheni Sinev, 1999, but differs from them in: (i) thin setulae between the marginal setae on the valves, (ii) setae 4-5 on the exopodite of limb III long and different in length, (iii) bottle-shaped sensillum on the basal endite of limb IV. For identification of Alona margipluma sp. nov. it is necessary to check carefully the main head pores and postabdomen characters since the former superficially resemble A. iheringula, A. setigera and Alona guttata.

New records of Anthalona acuta Van Damme, Sinev & Dumont 2011 and Anthalona brandorffi (Sinev & Hollwedel, 2002) in Brazil, with description of a new species of the simplex-branch (Crustacea: Cladocera: Chydoridae).

The range of geographical distribution of Anthalona acuta Van Damme, Sinev & Dumont 2011 and Anthalona brandorffi (Sinev & Hollwedel, 2002) in Brazil has increased by almost 2000 km to the south. New records of Anthalona verrucosa verrucosa (Sars, 1901) were also added. Populations of Anthalona brandorffi from Central Brazil showed a peculiar morphological variation, with some individuals having only a single denticle on the labral keel. A new species of the simplex-branch, Anthalona neotropica sp. nov., was described based on Brazilian material, and this is the first taxon of this branch registered in the Neotropics. It differs from Anthalona simplex Van Damme, Sinev & Dumont 2011, a Central African species, in the morphology of underneath sack of the lateral head pores, length of IDL setae and armature of first flaming-torch seta of limb IV. It could be distinguished from Anthalona sanoamuangae Sinev & Kotov, 2012 (distributed through the South- East Asia) by the morphology of the main head pores, length of IDL setae and armature of the pecten of postabdominal claw. Anthalona neotropica sp. nov. seems to have a benthic/hyporheic habit. All studied species have a wide geographical distribution and could be confused with Anthalona verrucosa Sars, 1901, thus at least some if not all previous records of this species on the continent must be revised.

Ephemeroporus quasimodo sp. nov. (Crustacea: Cladocera: Chydoridae), a new species from the Brazilian Cerrado.

A new species of Chydoridae cladoceran (Crustacea: Cladocera: Chydoridae) is described from the Cerrado (a Brazilian tropical savanna ecoregion), Central Brazil. Ephemeroporus quasimodo sp. nov. differs from other species of the genus in a high dorsal keel on carapace and posterior part of the head shield, which resembles a hunchback. Parthenogenetic females, ephippial females and males are described, including details of trunk limb morphology. The species is endemic to shallow wetlands found in the Cerrado, where pristine conditions are preserved. Some questions on genus morphology and taxonomic status of Ephemeroporus species occurring in Brazil are discussed.

Redescription of Alonella lineolata Sars, 1901 (Crustacea, Cladocera, Chydoridae) and its translocation to the subfamily Aloninae and to the new genus Bergamina gen. nov.

Alonella lineolata Sars 1901 (Anomopoda, Chydoridae) was described from a single female found in an aquarium prepared with dried mud from São Paulo, Brazil, and just recently this taxon has been reported again. The taxonomic status of A. lineolata was previously questioned, but re-evaluation was not possible until now due to the lack of specimens. The present paper described parthenogenetic females, based on specimens collected in a small pond at Prad6polis, state of São Paulo, and a specimen was selected as neotype. The head pores, mandibles, and the trunk limb morphology revealed that this species belongs to the subfamily Aloninae, instead of Chydorinae, as presumed by Sars. Despite its Alona-like aspect, this species presents a unique combination of characters, leading to its assignment to a new alonine genus, Bergamina gen. nov.