Abstract The study of Colombian freshwater crabs has advanced significantly, but species records are scattered across different museums and research institutions. Assuming that museum collections incorporate valuable information in estimating species diversity, a database was organized on the 94 known species of family Pseudothelphusidae, which includes 568 records from 1853 to 2019 in continental Colombia and Gorgona Island. The natural regions of Colombia (Amazonian, Andean, Caribbean, Orinoquian, Pacific) were further subdivided into 75 natural sub-regions according to habitat types used by freshwater crabs. Sub-regions were (i) ranked in terms of species richness, with respective species reported in each sub-region listed accordingly, and (ii) classified into a scale of five categories on the basis of a geometric biodiversity index combining species richness and Simpson index. Species accumulation curves are presented to estimate the current status of knowledge about the diversity of the Colombian pseudothelphusids. Although the available data are not standardized for an adequate assessment of relative abundance, since they are influenced by sampling efforts and natural sub-regions are of different sizes and characteristics, the present study may be useful in future ecological and biogeographic research, as well as for conservation purposes.

Resumen En este estudio se identifican las variaciones morfológicas a nivel del caparazón, pereópodos, exognatos del tercer maxilípedo y gonópodos de 333 especímenes de Neostrengeria charalensis provenientes de ambientes exo y endocársticos. La relación de la longitud del exognato respecto al isquio del endognato del tercer maxilípedo presenta un promedio de 0,55 para los especímenes de origen epigeo y 0,59 para los de origen hipogeo. Se estableció que existen diferencias entre la proporción de la longitud total del segundo pereópodo versus el ancho del caparazón, siendo mayor esta proporción en los especímenes de hábitos hipogeos frente a los epigeos. A nivel del gonópodo se describen y se ilustran las diferencias de especímenes provenientes de cuevas y cavernas. Se establecieron diferencias importantes en las proporciones a nivel morfológico, aunque estas no correspondieron a grandes variaciones. El resultado más relevante de este estudio es la evidencia de la existencia de una respuesta adaptativa por parte de los especímenes de hábitos hipogeos a su ambiente. Adicionalmente se incluyen algunos aspectos sobre la distribución, hábitat y bioecología de esta especie en ambientes hipogeos.

Abstract In this study, morphological variations are established at the level of the carapace, pereopods, exognath of the third maxilliped and gonopod of 333 specimens of freshwater crabs of the species Neostrengeria charalensis from exo and endocarstic environments. The relationship of the length of the exognath to the ischium of the endognath of the third maxilliped presents an average of 0.55 for specimens of epigeal origin and 0.59 for hypogeal specimens. It was established that there are differences between the proportions of the total length of the second pereopod versus the width of the carapace, being greater this proportion in the specimens of hypogean habits in comparison to those with epigean habits. At the gonopod level, differences in cave specimens were described and illustrated. Relevant differences were found in morphological proportions, but these do not represent large variations. The importance of this study is that it allows us to conclude that there is an adaptive response by the specimens of hypogeous habits to their environment. Additionally, some aspects about the distribution, habitat and bioecology of this species in hypogeous environments are included.

Resumen Se registra por primera vez para Colombia (cuenca del Orinoco), cuatro especies de crustáceos ectoparásitos en rayas de agua dulce (Potamotrygonidae), género Potamotrygon. Dos que pertenecen a la subclase Branchiura, familia Argulidae: Dolops reperta (Bouvier, 1899) y D. striata (Bouvier, 1899) y dos al orden Isopoda, correspondientes a las familias Cymothoidae y Corallanidae, representadas con las especies Braga cigarra (Szidat & Schubart, 1960) y Excorallana delaneyi (Stone & Heard, 1989), respectivamente.

Abstract Four species of ectoparasite crustaceans are registered for the first time from the Orinoco River Basin (Colombia) in freshwater stingrays of the family Potamotrygonidae, genus Potamotrygon. Two belong to the Branchiura subclass, Argulidae family: Dolops reperta (Bouvier, 1899) and D. striata (Bouvier, 1899), and two to the Isopoda Order, corresponding to the families Cymothoidae and Corallanidae, represented by the species Braga cigarra (Szidat & Schubart, 1960) and Excorallana delaneyi (Stone & Heard, 1989), respectively.

ABSTRACT Hypolobocera olgaluciae Ramos-Tafur and Ríos, 2007 is considered herein as junior synonym of H. buenaventurensis (Rathbun, 1905) taking into account that the morphological differences on the first male gonopod are not significant and are the consequence of natural variations of the populations. The first male gonopod of H. buenaventurensis is redescribed and illustrated.

Se presentan nuevos registros de Macrobrachium digueti (Bouvier, 1895) de Acandí, corregimiento de Sapzurro e inspección de Capurganá, departamento de Chocó, Colombia. Se incluye la diagnosis, la descripción e ilustraciones de la especie con base en la morfología del rostro, el telson y el segundo par de pereopodos. Se analiza la distribución geográfica de M. digueti, teniendo en cuenta que los nuevos registros extienden su distribución desde la región Pacífica a la región Caribe.

New records of Macrobrachium digueti (Bouvier, 1895) from Acandí, corregimiento Sapzurro and inspecciónCapurganá, department of Chocó, Colombia, are presented. The diagnosis, description and illustrations of this species, based on the morphology of the rostrum, the telson and the second pair of pereopods, are included. The geographical distribution of M. digueti is analyzed taking into account that the new records extend the distribution from the Pacific to the Caribbean region.

Una nueva especie de cangrejo pseudothelphusido del género Neostrengeria Pretzmann, 1965, es descrita e ilustrada. Este descubrimiento significa que el género ahora contiene 25 especies, endémicas de los Andes Orientales de Colombia. La nueva especie se distingue de sus congéneres principalmente por la morfología del primer gonopodo del macho, particularmente por las formas del lóbulo accesorio, del ápice y del lóbulo mesial

A new species of freshwater crab of the pseudothelphusid genus Neostrengeria Pretzmann, 1965, is described and illustrated. This discovery means the genus now contains 25 species, all of which are endemic to the Eastern Andes of Colombia. The new species is distinguished from their congeners primarily by the morphology of the first male gonopod, particularly by the shape of the accessory lobe, outline of apex and mesial lobe.

Se describen dos nuevas especies de Neostrengeria Pretzmann, 1965, N. bataensis, de Santa María, Departamento de Boyacá y N. celioi, de Aguazul, Departamento de Casanare, en la vertiente oriental de los Andes Orientales. Con la adición de las nuevas especies, el número de especies del género se incrementa a 23. Las nuevas especies se diferencian de las otras del género principalmente en la morfología del primer gonopodo del macho, particularmente en la forma de los lóbulos laterales y accesorios, el contorno del ápice, la proyección mesocaudal y el lóbulo mesial. El género Neostrengeria es endémico de Colombia y se distribuye en las dos vertientes y el altiplano de la Cordillera Oriental, en un rango de elevación de 470 a 3000 m. Se presenta una clave para la identificación de las especies basada esencialmente en la morfología del primer gonopodo del macho y de los pereopodos.

We describe two new species of Neostrengeria Pretzmann, 1965, N. bataensis, from Santa María, Boyacá Department, and N. celioi, from Aguazul, Casanare Department, on the eastern slope of the Eastern Andes. With the addition of the new species, the number of species in the genus rises to 23. These new species are distinguished from their congeners primarily by the morphology of the first male gonopod, particularly by the shape of the lateral and accessory lobes, outline of apex, mesocaudal projection and mesial lobe. The genus Neostrengeria is endemic to Colombia and is distributed in both slopes and the high plain of the Eastern Cordillera, at elevations ranging from 470 to 3000 m. We present a key for the identification of the species based essencially on the morphology of the first male gonopod and pereopods.

Se propone considerar las especies H. solimani e H. triangula como sinónimos de H. alata e H. rotundilobata, respectivamente. Se afirma que las diferencias morfológicas a) del primer gonopodo, del tercer maxilipedo y de la quela mayor entre H. alata e H. solimani y b) las diferencias del primer gonopodo entre H. rotundilobata e H. triangula, no son significativas y se originan en variaciones naturales propias de las poblaciones.

A proposal to synonymize the freshwater crab species Hypolobocera solimani and Hypolobocera triangula from Colombia. It is proposed that Hypolobocera solimani and H. triangula be considered junior synonyms of H. alata and H. rotundilobata, respectively. We state that the following morphological differences represent natural variations within the population: a) first male gonopod, third maxilliped and larger cheliped between H. alata and H. solimani, and b) the differences of the first male gonopod between H. rotundilobata and H. triangula. Rev. Biol. Trop. 56 (3): 987-994. Epub 2008 September 30.