Thursday 29 January 2015

A new genus of Goblin Spiders from Costa Rica.


In 1938 Jean-Louis Fage of the Muséum National d’Histoire Naturelle de Paris described a new species of Goblin Spider (tiny Spiders generally found living in soil or leaf litter) from a single male specimen from the collection of the Natural History Museum of Vienna as Xestaspis reimoseri, which had apparently been found in a Termite nest in Costa Rica, the only species of Xestaspis ever recorded from the Americas. Since this time the specimen from which Fage described the species has been lost, though the Vienna Museum do still have details of the specimen not provided in Fage’s description, notably the location where it was collected, Hamburg Farm on the banks of the Río Reventazón near Cairo in Limón Province. Hamburg Farm was run by a German entomologist, Ferdinand Nevermann, and after his death the property was acquired by a large Banana company and ceased to exist as a separate property, though a local village still retains the name Hamburg.

In a paper published in the American Museum Novitates on 22 December 2014, Norman Platnick and Lily Berniker of the Division of Invertebrate Zoology at the American Museum of Natural History and Carlos Víquez of the Instituto Nacionalde Biodiversidad in Santo Domingo, Costa Rica, describe a series of specimens from trees at Estación Biológica La Selva in Heredia Province, which they believe to be the same species as Fage’s specimen. They move the species to a new genus, Hexapopha, meaning ‘Six-eyes’ and also implying a similarity to Coxapopha, and describe three further species from Costa Rica, which they also place in this new genus.

The new specimens of Hexapopha reimoseri are a female found in a tree hole with large Ants, a male collected from epiphytic root fibres (i.e. roots produced in the canopy by plants living on branches, to absorb moisture from the air), two males collected from a Virola koschnyi tree (Wild Nutmeg) by fogging (spraying a tree with insecticide and seeing what drops out), and a male collected from by the Camino Experimental Sur 830 m altitude marker. The males average 1.54 mm in length, the females 1.83 mm. Based upon these specimens, it is considered that the species is arboreal in nature (tree dwelling), rather than ground dwelling, and that Fage’s specimen probably came from a tree-living Termite nest.

Hexapopha reimoseri, scanning electron microscope image, male in dorsal view. Platnick et al. (2014).

The first new species described is named Hexapopha hone, in reference to the site where the specimens was collected, at Hone Creek in Limón Province. The species is described from two specimens, a male and a female, collected by beating bushes in an abandoned Cacao field on the farm of Alberto Moore. The male is 1.41 mm in length, the female 1.74 mm.

Hexapopha hone, male in (76) dorsal view and (77) lateral view, female in (79) dorsal view and (80) lateral view. Platnick et al. (2014).

The second new species described is named Hexapopha jimenez, after Puerto Jiménez in Puntarenas Province, close to where one of the specimens was collected. The species is described from two female specimens, one from the collection of the Museum of ComparativeZoology at Harvard University, collected from an unknown substrate 13 km to the southwest of Puerto Jiménez, the other from the collection of the Instituto Nacional de Biodiversidad, collected from humus (soil) at an unknown location in Costa Rica. The specimens are 1.74 mm in length.

Hexapopha jimenez, female specimen in dorsal view. Platnick et al. (2014).

The third new species described is named Hexapopha osa, after the Península de Osa in Puntarenas Province, where the specimens from which the species is described were collected. The species is described from two females collected from an unknown substrate at Rancho Quemado, two males collected from humus at Sirena, a female collected from a log at the Tropical Science Center, 5 km  to the west of Rincón de Osa, a male collected from leaf litter on a ridge close to the same log, a male collected from a decomposed log, also at the Tropical Science Center, and two males and a female, collected from a slightly decomposed log at an angle of 45° in a stream bed, also at the Tropical Science Center. The males average 1.69 mm in length and the females 1.87 mm.

 

Hexapopha osa, male in (111) dorsal view and (112) lateral view, female in (114) dorsal view and (115) lateral view. Platnick et al. (2014).

See also…

http://sciencythoughts.blogspot.co.uk/2012/12/goblin-spiders-from-cretaceous-amber.htmlGoblin Spiders from Cretaceous Amber.    Goblin Spiders (Oonopidae) are one of the most abundant groups of Spiders, with at least 600 and possibly over 1000 extant species described, though this is generally considered to be a poor representation of their diversity, since the Spiders are tiny (often unde...
Follow Sciency Thoughts on Facebook.