Thereza cf. speciosa - Thereza Harvestman (Roewer, 1913)

Arachnida: Opiliones: Laniatores: Grassatores: Gonyleptoidea: Gonyleptidae: K92: Caelopyginae

Date: 25th of March, 2017 at 03:03:22pm.

The location specified on the map is approximate but not accurate.

Their habitats are wet forests and caverns. The subject portrayed was found in an untouched forest in the neighborhoods of Benedito Novo in Santa Catarina in Brazil.

Thereza is a genus of harvestmen with five known species:

Thereza speciosa
Thereza albiornata
Thereza amabilis
Thereza murutinga
Thereza poranga

They are members of the class Arachnida, order Opiliones, suborder Laniatores, infraorder Grassatores, superfamily Gonyleptoidea, family Gonyleptidae, unranked clade K92 and subfamily Caelopyginae.

I suspect the subject portrayed is a Thereza speciosa. After some research, I came upon this image in the Internet, the only existing image of Thereza speciosa in the Internet besides mine which is also available in this post's references: https://vignette.wikia.nocookie.net/opiliones/images/9/91/Thereza_speciosa.jpg/revision/latest?cb=20140918024315

If you compare both, there is a very slight difference in patterns. There are no pictures of the other species of Thereza in the Internet besides one of a male of T. murutinga:

https://www.researchgate.net/publication/245535776_Descriptions_of_Thereza_murutinga_sp_nov_and_Pristocnemis_caipira_sp_nov_and_new_records_of_Caelopyginae_Opiliones_Laniatores_Gonyleptidae

Judging by the two pictures, the subject portrayed is most likely a Thereza speciosa since the pattern variation is very slight and it could just be a normal alteration among individuals; either that, or it is one of the other 3 species with no pictures in the Internet.

Harvestmen are related to spiders, but different as well. The cephalothorax and abdomen are fused together, they possess penis and ovipositor and a couple of odor glands. Harvestmen are harmless. Most of them are adapted to dark, wet places such as humid forests and caverns. They are morphologically adapted to these places by possessing sensorial parts that they use to interact within the area. Generally, cave-dwelling species use chemical and mechanical signals to communicate with the opposite sex and to find food. Harvestmen adapted to a variety of biomas, also being able to dwell in dry places, but most live in dark, wet places such under rocks and trunks.

They are predators, feeding on small invertebrates. They are known to practice cannibalism, eating other harvestmen, dead or alive. A few are saprophagous, while others suck vegetable juice, but most are omnivorous. Harvestmen are able to eat solid substances.

They are mostly nocturnal and serve as food to frogs, ants, crickets, wasps and other harvestmen. They are known to release a repugnant yellowish liquid to repel predators. Some can autotomize their legs or feing death.

Generally, either the male or the female protect the eggs, being able to protect them for a whole month without feeding if needed. In fact, many species show great paternal and maternal care behaviour. Some species are known to be less careful.

Sources:

Opiliones Wikia: http://opiliones.wikia.com/wiki/Thereza_speciosa
EOL: http://eol.org/pages/43804819/overview
Caelopyginae: https://en.wikipedia.org/wiki/Caelopyginae