Metagonia diamantina, Machado & Ferreira & Brescovit, 2011

Machado, On. O., Ferreira, Rodrigo L. & Brescovit, Io. D., 2011, A new troglomorphic Metagonia Simon 1893 (Araneae, Pholcidae) from Brazil, Zootaxa 3135 (1), pp. 59-62 : 59-62

publication ID

https://doi.org/ 10.11646/zootaxa.3135.1.4

DOI

https://doi.org/10.5281/zenodo.5246399

persistent identifier

https://treatment.plazi.org/id/03F9351A-AF56-C00D-3ADF-444FCD97FE14

treatment provided by

Felipe

scientific name

Metagonia diamantina
status

sp. nov.

Metagonia diamantina View in CoL new species

( Figures 1–11 View FIGURES 1–8 View FIGURES 9–11 )

Type material. Male holotype and paratype female from Lapa do Bode cave (12º56'02"S; 41º03'44"W), Itaeté, Bahia, Brazil, 26.VII.2007, R. L. Ferreira col., deposited in ISLA 1429 and ISLA 1428, respectively GoogleMaps .

Etymology. The specific name is a noun in apposition taken from the Chapada Diamantina, a famous Brazilian region where the cave is located.

Diagnosis. The species is compared with the other three eyeless Metagonia species. Metagonia diamantina can be distinguished from M. bellavista and M. debrasi by the unpaired apophysis on the male clypeus ( Figs. 4 View FIGURES 1–8 , 10 View FIGURES 9–11 ) and the epigynal scape ( Figs. 7–8 View FIGURES 1–8 ), and from M. reederi by the long, divided and strong procursus ( Fig. 3 View FIGURES 1–8 ), the smooth chelicerae ( Fig. 5 View FIGURES 1–8 ) and the epigynal scape ( Figs. 7–8 View FIGURES 1–8 ).

Description. Male (Holotype). Total length 1.8, carapace length 0.7, width 0.7, leg I 13.3 (3.3 + 0.4 + 3.6 + 5.0 + 1.1), tibia II 2.5, tibia III 1.8, tibia IV 2.3; tibia I l/d 40. Habitus as in figures 9–10. Carapace slightly indented medially but without thoracic groove ( Fig. 9 View FIGURES 9–11 ), homogeneous pale yellow without stripes or spots ( Figs. 9–10 View FIGURES 9–11 ), almost depigmented. Ocular area undifferentiated, eyeless, without lens or ocular pigmentation. Clypeus with a simple pointed apophysis ( Figs. 4–5 View FIGURES 1–8 ). Sternum pale yellow. Chelicerae pale yellow, without apophyses or modified hairs ( Fig. 5 View FIGURES 1–8 ). Palps ( Figs. 1–3 View FIGURES 1–8 ) pale yellow; femur without apophysis; trochanter with strong ventral apophysis; procursus divided distally, hinged process elongated and strong ( Fig. 3 View FIGURES 1–8 ), general color pale yellow, darkening to dark brown on the tips; bulb simple with a slender embolus ( Fig. 2 View FIGURES 1–8 ). Legs pale yellow, spines absent, retrolateral trichobothrium of tibia I at 6%, tarsus I with approximately 18 pseudosegments. Abdomen globular ( Figs. 9–10 View FIGURES 9–11 ), completely pale yellow, genital plate indistinct.

Female (paratype). Total length 2.5, carapace length 0.8, width 0.9, leg I 14.3 (3.8 + 0.4 + 3.7 + 5.3 + 1.1), tibia II and III missing, tibia IV 3.6. In general very similar to male, eyeless and without clypeus modification ( Fig. 6 View FIGURES 1–8 ). Habitus as in fig. 11. Epigynum pale yellow, the epigynal plate with distinct scape ( Figs. 7 View FIGURES 1–8 ). Internal genitalia with a complex system of asymmetrical, sclerotized ducts ( Fig. 8 View FIGURES 1–8 ).

Distribution. Known only from the type locality.

Other material examined. None.

Remarks. The species probably belongs to Huber (2000) ’s ‘group 4’. It shows similarities to M. lancetilla Huber 1998 , sharing the long hinged process and the epigynal scape (very small in M. lancetilla ).

Habitat description and natural history. The two specimens were collected in an inner portion of the Lapa do Bode cave (approximately 200 meters from the nearest entrance), in a chamber with moist soil and some bat guano piles. The specimens were moving slowly on the cave floor, and they were found at least 40 meters apart from each other. The potential preys observed in the cave were mainly springtails ( Arrhopalitidae and Cyphoderidae , both troglomorphic).

The Lapa do Bode cave has 1,430 meters of horizontal projection, with conduits of anastomotic pattern. Although the cave is mainly dry, the existence of some water ponds in some inner areas enhances the moisture content in the cave atmosphere (in some parts of the cave the moisture content is 100%). The temperature inside the cave is around 24.5ºC. The cave is currently being used for touristic purposes, and the area where the spiders were found is visited. Although these activities are not apparently altering intensively the cave (there are no electric lights), there is concern that the touristic activities could have an impact on the species.

R

Departamento de Geologia, Universidad de Chile

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Pholcidae

Genus

Metagonia

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