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.

New records of Harpacticoids (Crustacea, Copepoda) from a coastal system of northern Colombia

Three species of harpacticoids are herein recorded from the zooplankton of Rodadero beach, Santa Marta, Magdalena, Colombia. Samples were collected from the littoral zone, mainly at inshore areas covered by mangrove vegetation and in an adjacent oyster bank. One of them, Laophonte cornuta Philippi, 1840 is new to the Colombian harpacticoid fauna, the other two species: Distioculus minor (Scott T., 1894) and Microsetella norvegica (Boeck, 1865) are new reports to the Magdalena department. This is the first illustrated record confirming their presence in Colombia and Magdalena, northern Colombia. Comparative morphological comments and illustrations of these species are also provided to document this report.

Se registran tres especies de harpacticoides en el zooplancton de playa Rodadero, Santa Marta, Magdalena, norte de Colombia. Se recolectaron muestras en la zona litoral, principalmente en áreas costeras de manglar y en un banco de ostras. Una de ellas, Laophonte cornuta Philippi, 1840 es nueva para la fauna de harpacticoides de Colombia; las otras dos especies: Distioculus minor (Scott T., 1894) y Microsetella norvegica (Boeck 1865) son nuevos reportes para el departamento del Magdalena. Este es el primer registro ilustrado que confirma su presencia en Colombia y Magdalena. Se proporcionan comentarios morfológicos comparativos e ilustraciones de estas especies.

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.

A NEW SPECIES OF Halicyclops (Copepoda, Cyclopoida, Halicyclopinae) FROM AN ESTUARINE SYSTEM OF THE CARIBBEAN COAST OF COLOMBIA / Una nueva especie de Halicyclops (Copepoda, Cyclopoida, Halicyclopinae) de un sistema estuarino de la Costa Caribe de Colombia

ABSTRACT Plankton samples obtained from the Ciénaga Grande de Santa Marta, an extensive estuarine system in northern Colombia, yielded adult male and female specimens of an undescribed halicyclopine cyclopid copepod of the genus Halicyclops. Cyclopid copepods are frequently found in freshwater and transitional habitats. Members of the subfamily Halicyclopinae are chiefly brackish water forms with a few freshwater species. The new species described herein is assignable to the group of species "F" of Halicyclops (sensu Pesce, 2018) with a 2333 exopodal spine formula. Currently, this group contains five species and one subspecies. Halicyclopsgutierrezi sp. n. can be distinguished from its known congeners by the absence of an anal operculum, the relative length of setae of the female and male P5, the relative length of the inner setae of P4EXP3, and details of the male antennule. This is the fifth species of Halicyclops recorded from Colombia and the first one of Halicyclops group "F" described from the Caribbean region. With the addition of H. gutierrezi sp. n., the number of species of the genus known from the Neotropics increased to 20. A key to the species of the genus recorded in Colombia is also provided.

RESUMEN Muestras de plancton obtenidas de la Ciénaga Grande de Santa Marta, un extenso sistema estuarino en el norte de Colombia, produjeron especímenes machos y hembras de una especie no descrita del género Halicyclops. Los copépodos de la familia Cyclopidae son dominantes en los hábitats de agua dulce y transicionales. Los miembros de la subfamilia Halicyclopinae son predominantemente de hábitats salobres, con algunas especies de agua dulce. La nueva especie aquí descrita es asignable al grupo de especies denominado "F" de Halicyclops (sensu Pesce, 2018) con una fórmula de espinas exopodales (P1-4) = 2333. Actualmente, este grupo contiene cinco especies y una subespecie. Halicyclops gutierrezi sp. n. puede distinguirse de sus congéneres conocidos por la ausencia de un verdadero opérculo anal, la longitud relativa de las setas de la P5 de la hembra y del macho, la longitud relativa de las setas internas de P4EXP3 y por detalles de la anténula del macho. Esta es la quinta especie de Halicyclops registrada en Colombia y la primera del grupo "F" de Halicyclops descrita en la cuenca del Caribe. Con la adición de H. gutierrezi sp. n., aumentó a 20 el número de especies del género que se conocen en la región Neotropical. Se proporciona una clave para la identificación de las especies del género registradas en Colombia.

Avaliação da qualidade da água do Ribeirão Samambaia (São Pedro, São Paulo, Brasil) através de parâmetros físicos e químicos, índice de estado trófico e teste de toxicidade com Daphnia magna / Water quality assessment in Samambaia Creek (São Pedro, São Paulo, Brazil) through physical chemical parameters, trophic state index and toxicity test with Daphnia magna

RESUMO O objetivo deste trabalho foi avaliar a qualidade da água do Ribeirão Samambaia (São Pedro, São Paulo, Brasil) utilizando parâmetros físicos e químicos, índice de estado trófico (IET) e ensaio ecotoxicológico com Daphnia magna. De janeiro a dezembro de 2011, amostras de água foram coletas mensalmente à montante e à jusante de São Pedro e dentro da cidade, e expostas a D. magna em laboratório durante 48 horas para avaliar efeitos sobre sua mobilidade. Condutividade, fenóis, oxigênio dissolvido, demanda bioquímica de oxigênio, surfactantes, pH e IET foram mensurados. Valores dos cinco primeiros parâmetros demonstraram baixa qualidade da água à jusante da cidade. Valores de clorofila-a estiveram dentro do permitido pela legislação ambiental brasileira e, dessa forma, o IET das águas do Ribeirão Samambaia foi classificado como ultraoligotrófico para a maioria dos locais e meses amostrados. Amostras de água coletadas de janeiro a abril à jusante de São Pedro foram tóxicas para D. magna. De acordo com as características físicas e químicas e o ensaio ecotoxicológico, conclui-se que o Ribeirão Samambaia possui baixa qualidade da água após a cidade de São Pedro.

ABSTRACT The goal of this study was to evaluate the water quality of Samambaia Creek (São Pedro, São Paulo, Brazil) through physical chemical parameters, trophic state index (TSI) and ecotoxicological assay with Daphnia magna. From January to December 2011 water samples were monthly collected from upstream, downstream and inside the São Pedro city, and exposed to D. magna in laboratory for 48 hours to evaluate mobility effects. Conductivity, phenols, dissolved oxygen, biochemical oxygen demand, surfactants, pH, and TSI were measured. Values of the first five parameters showed low water quality downstream of the city. Chlorophyll a values ​​were within the range permitted by the Brazilian environmental legislation and thus the TSI in Samambaia Creek was classified as ultra-oligotrophic for most sites and months. Water samples collected from January to April downstream of São Pedro were toxic to D. magna. The physical chemical analysis and the toxicity test indicate low quality of water from Samambaia Creek downstream the city of São Pedro.

Length-weight relationships and biomass of the main microcrustacean species of two large tropical reservoirs in Brazil / Regressoes peso-comprimento e biomassa das principais especies de microcrustaceos de dois grandes reservatorios tropicais no Brasil

Length-weight equations were determined for the main microcrustacean species of Três Marias and Furnas reservoirs (state of Minas Gerais, Brazil), and evaluated the fluctuations of their biomass. We examined the following species: Thermocyclops minutus, Bosminopsis deitersi, Bosmina hagmanni, Ceriodaphnia cornuta, and Moina minuta (Três Marias Reservoir), and Notodiaptomus henseni, Daphnia ambigua, Ceriodaphnia silvestrii, Diaphanosoma spinulosum, D. fluviatile, and Bosmina freyi (Furnas Reservoir). Dry weight was obtained in a microbalance for each size class (Cladocera) or developmental stage (Copepoda). Microcrustacean mean biomass varied from 5.76 mg DW.m−3 and 20.36 mg DW.m−3 (Furnas Reservoir) and from 3.75 mg DW.m−3 and 18.14 mg DW.m−3 (Três Marias Reservoir). Significant differences (p < 0.000) between seasons were registered with higher biomass during the rainy seasons. Thermocyclops minutus was the most important species in Três Marias, whereas in Furnas, N. henseni contributed in equal proportion. In Furnas, the higher cladoceran biomass was explained by the contribution of larger-sized species, such as D. ambigua, C. silvestrii, D. spinulosum, and D. fluviatile. Even though both reservoirs are considered oligotrophic, there were significant differences in the estimated microcrustacean biomass, which reinforces the importance of this parameter for the description of the real contribution of each species in the community.

Equações peso-comprimento foram determinadas para as principais espécies de microcrustáceos dos reservatórios de Três Marias e Furnas (Minas Gerais, Brasil), assim como a flutuação de sua biomassa. Foram consideradas as espécies mais abundantes: Thermocyclops minutus, Bosminopsis deitersi, Bosmina hagmanni, Ceriodaphnia cornuta, e Moina minuta (Reservatório de Três Marias) e Notodiaptomus henseni, Daphnia ambigua, Ceriodaphnia silvestrii, Diaphanosoma spinulosum, D. fluviatile e Bosmina freyi (Reservatório de Furnas). O peso seco foi obtido em microbalança para cada classe de tamanho no caso dos Cladocera ou para cada estágio do desenvolvimento no caso dos Copepoda. Valores médios de biomassa dos microcrustáceos variaram de 5,76 mg PS.m−3 a 20,36 mg PS.m−3 (Reservatório de Furnas) e de 3,75 mg PS.m−3 a 18,14 mg PS.m−3 (Reservatório de Três Marias), durante os períodos de seca e chuva, respectivamente. Diferenças significativas (p < 0.000) foram registradas entre os períodos com maior biomassa durante os períodos de chuva. Thermocyclops minutus foi a espécie mais importante em Três Marias, enquanto em Furnas, N. henseni contribuiu em igual quantidade para a biomassa. Em Furnas, a maior biomassa de Cladocera foi observada devido a espécies de maior tamanho corporal como D. ambigua, C. silvestrii, D. spinulosum, e D. fluviatile. Mesmo ambos os reservatórios considerados oligotróficos, há diferenças significativas na biomassa de microcrustáceos, que reforçam a importância deste parâmetro para determinar a real contribuição de cada espécie na comunidade.

Bioindicators of climate and trophic state in lowland and highland aquatic ecosystems of the Northern Neotropics

Chironomids, diatoms and microcrustaceans that inhabit aquatic ecosystems of the Northern Neotropics are abundant and diverse. Some species are highly sensitive to changes in water chemical composition and trophic state. This study was undertaken as a first step in developing transfer functions to infer past environmental conditions in the Northern lowland Neotropics. Bioindicator species abundances were related to multiple environmental variables to exploit their use as environmental and paleoenvironmental indicators. We collected and analyzed water and surface sediment samples from 63 waterbodies located along a broad trophic state gradient and steep gradients of altitude (~0-1 560m.a.s.l.) and precipitation (~400-3 200mm/y), from NW Yucatán Peninsula (Mexico) to southern Guatemala. We related 14 limnological variables to relative abundances of 282 diatom species, 66 chironomid morphospecies, 51 species of cladocerans, 29 non-marine ostracode species and six freshwater calanoid copepods. Multivariate statistics indicated that bicarbonate is the strongest driver of chironomid and copepod distribution. Trophic state is the second most important factor that determines chironomid distribution. Conductivity, which is related to the precipitation gradient and marine influence on the Yucatán Peninsula, is the main variable that shapes diatom, ostracode and cladoceran communities. Diatoms, chironomids and cladocerans displayed higher diversities (H=2.4-2.6) than ostracodes and copepods (H=0.7- 1.8). Species richness and diversity were greater at lower elevations (<450m.a.s.l.) than at higher elevations in Guatemala. Distribution and diversity of bioindicators are influenced by multiple factors including altitude, precipitation, water chemistry, trophic state and human impact.

Los quironómidos, diatomeas y microcrustaceos que habitan ecosistemas acuáticos en el norte de los Neotrópicos son abundantes y diversos. Algunas especies son altamente sensibles a cambios en la composición química del agua y en el estado trófico. Este estudio se realizó como el primer paso para desarrollar funciones de transferencia para inferir condiciones ambientales en el norte de las tierras bajas de los Neotrópicos. Es por esto que las abundancias de especies bioindicadoras se relacionaron con múltiples variables ambientales con el fin de explotar al máximo su uso como indicadores ambientales y paleoambientales. Recolectamos y analizamos muestras de agua y de sedimento superficial de 63 cuerpos de agua, ubicados a lo largo de un gradiente trófico y de gradientes marcados de altitud (~0-1 560m.s.n.m.) y de precipitación (~400-3 200mm/año), desde el NO de la Península de Yucatán (México) hasta el sur de Guatemala. Relacionamos 14 variables limnológicas con las abundancias relativas de 282 especies de diatomeas, 66 morfoespecies de quironómidos, 51 especies de cladóceros, 29 especies de ostrácodos no-marinos y seis especies de agua dulce de cladóceros calanoides. La estadística multivariada indicó que el bicarbonato es el principal determinante de la distribución de quironómidos y copépodos. El estado trófico es el segundo factor más importante en determinar la distribución de quironómidos. La conductividad, que está relacionada con el gradiente de precipitación e influencia marina en la Península de Yucatán, es la principal variable en influir las comunidades de diatomeas, ostrácodos y cladóceros. Las diatomeas, quironómidos y cladóceros (H=2.4-2.6) presentaron diversidades más altas que los ostrácodos y copépodos (H=0.7-1.8). La riqueza de especies y la diversidad fueron más altas en las elevaciones bajas (<450m.s.n.m) que en elevaciones altas en Guatemala. La distribución y diversidad de bioindicadores es afectada por múltiples factores incluyendo la altitud, precipitación, composición química del agua, estado trófico y el impacto humano.

Diversity and abundance of littoral cladocerans and copepods in nine Ecuadorian highland lakes

The diversity and abundance of littoral cladocerans and copepods were studied in nine lakes at Reserva Ecológica Cayambe-Coca (Páramo de Guamaní), Ecuador. Six samples were taken in the littoral zone of each lake using a 500 µm mesh plankton conic net. One species of cladocerans (Ephemeroporus acanthoides) is reported for the first time in Ecuador. The diversity (H’) and evenness (E) of the lakes were determined and correlated with PCA axes based on their environmental variables. The principal parameters that distinguished these lakes were altitude and pH, an unexpected finding considering that the altitudinal range was very small. Lake size is of secondary importance for this group of lakes. None of the environmental axes correlated with H’ or E; nevertheless, a larger than expected species richness was found in a small oligotrophic lake with a high level of DO. Based on our results, we hypothesize that altitude and pH are important factors determining the zooplankton diversity (directly or indirectly) in highland lakes.

La diversidad y abundancia de cladóceros y copépodos de la zona litoral de nueve lagos fue estudiada en la Reserva Ecológica Cayambe-Coca (Páramo de Guamaní), Ecuador. Seis muestras fueron tomadas en la zona litoral de cada lago utilizando una red conica para plancton de 500 µm de apertura. Una especie de cladócero (Ephemeroporus acanthoides ) es informada por primera vez en Ecuador. La diversidad (H’) y equitatividad (E) fueron determinadas y correlacionadas con los ejes del PCA basado en variables ambientales de los lagos. Los principales parámetros que distinguen estos lagos fueron la altitud y el pH, hallazgo inesperado dado el estrecho ámbito altitudinal. El tamaño parece ser secundario en importancia para este grupo de lagos. No se encontró una correlación significativa entre ninguno de los ejes ambientales y los indices H’ o E; sin embargo, la riqueza de especies fue mayor en un pequeño lago oligotrófico con altos niveles de DO.