Wednesday, 10 October 2012

Nine new species of cave-dwelling huntsman spider from Laos.

Huntsman Spiders (Sparassidae) are large, active Spider from South East Asia, Australia, Africa, Southern Europe and the Americas, noted for their chasing down of prey and general aggressive behavior. The larger members of the group are often mistaken for Tarantulas, though they are not closely related. They are known by a variety of local names, including Crab Spiders, Cane Spider, Lizard Eating Spiders, Wood Spiders and Rain Spiders. The bite of Huntsman Spiders is often painful, but not considered dangerous, and the Spiders are quite likely to bite if handled or if they otherwise feel threatened; the females will defend their eggs vigorously.

In a paper published in the journal Zootaxa on 9 August 2012, Peter Jäger of the Senckenberg Research Institute describes nine new species of Huntsman Spider from caves in Laos; all are placed within a single genus, Sinopoda, which is restricted to eastern Asia.

The first new species described is named Sinopoda steineri, named in honour of Helmut Steiner, a collector of South East Asian cave biota, including the specimen, a single female Spider, from which this species is named. The specimen is a 12.7 mm brown spider collected from a limestone cave in Luang Nam Tha Province. 

Sinopoda steineri, in dorsal view. Jäger (2012).

The second new species described is Sinopoda tham, the word 'tham' being Lao for cave. The species is described on the basis of three male and sixteen female spiders found in caves in Oudomxai and Luang Nam Tha provinces. These Spiders are 13-22 mm in length.

Two specimens of Sinopoda tham from the Chom Ong cave system. Jäger (2012).

The third new species described is named Sinopoda sitkao, where the word 'sitkao' derives from the Lao word 'sîitkăao' meaning 'pale'; like many cave-dwelling species, Sinopoda sitkao, is pale in colour. The species is described from two female Spiders from a single cave in Luang Prabang Province, both 15.6 mm in length.

Sinopoda sitkaoJäger (2012).

The fourth new species described is named Sinopoda taa, 'taa' being a Lao word for eye, the spider having well developed eyes. The species is described from a single female specimen, 18.3 mm in length, from a limestone cave in Luang Prabang Province.

Sinopoda taa. Jäger (2012).

The fifth new species is named Sinopoda suang, 'suang' being a Lao word for hidden. This species is named from a single female Spider, 11.8 mm in length, from a cave in Huaphan Province.

Sinopoda suangJäger (2012).

The sixth new species described is named Sinopoda peet, 'peet' being the Lao word for eight (a reference to the eyes, not the legs). The species is named from a single 11.8 mm specimen from Huaphan Province.

Sinopoda peetJäger (2012).

The seventh new species described is named Sinopoda guap, where 'guap' means 'almost' or 'nearly' in Lao; the species has almost entirely lost its eyes (not uncommon in cave species). The species is described from an adult female and a juvenile from the same cave in Khammuan Province. The adult is 13.6 mm in length.

Sinopoda guap in dorsal (top) and frontal (bottom) views. Jäger (2012).

The eighth new species described is Sinopoda soong, where 'soong' means 'two' in Lao; the species having only two, much reduced, eyes. The species is named from one adult and one subadult female from caves in Khammuan Province. The adult is 15.1 mm in length.

Sinopoda soong in the wild (top) and in close up (bottom). Jäger (2012).

The ninth and final species described is named Sinopoda scurion, in honour of the Swiss electronics company, Scurion®, that supports conservation and research in Laos, and which makes headlamps used in caving. The species is described on the basis of five adult female specimens and 46 subadult and juvenile specimens of both sexes, all from a single cave in Khammuan Province. The adults are 10.9-13.6 mm in length, and the species completely lacks eyes.

Sinopoda scurion, in the wild (top), and detail of the head (bottom). Jäger (2012).

Map showing the distribution of known members of the genus Sinopoda in Laos. Jäger (2012).

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1 comment:

  1. There was a BBC documentary on giant Southeast Asia cave spiders last night.
    While in Viet Nam with the 173rd Abn Brigade in 1970 I was on an operation in Bin Din Province in II Corps where my unit was led to the VC underground headquarters by an escaped South Vietnamese POW. The VC kidnapped villagers in the area to control local populations through threats to family members kept in the POW camp. After our assault on a cave complex which contained ordinance, diagrams of our compounds within the AO, and enemy personnel whom we expelled from the cave complex it was our job to remove all remaining entail they left behind in their haste to be elsewhere. There we formed a "bucket brigade", bottom to top, to pass the various items upward in the cave to the next higher man until the the items reached the surface and were loaded on choppers to be taken to the rear for evaluation.
    My position in the cave was underground in very limited light where I laid on my back and passed grenades, typewriters, papers, and whatever was passed to me on to the next man above me in line. While laying there passing stuff I looked above me on the cave roof and there was a spider whose legs would have spanned a dinner plate, immobile above me, perhaps 2 feet away. I continued to pass items to the next man above me, but my eyes remained glued on the spider in the dimly lit cave right above my head. The creature never moved, but my gaze never left him after I saw him so near my head. I was quite relieved when the last item passed through my hands and we were told to exit the cave.
    After the cave complex was considered empty of valuables Chinook helicopters delivered 55 gallon drums of foo gas in nets that we poured into the cave entrances, drum after drum. Then we had an ordinance team set charges while the unit deployed to a hill that we could observe from a safe distance away.
    What I remember most besides the spider was the charge not going off and a sergeant being sent over to reset the explosive igniter. I am sure no spider survived the major burn when the charge did go off. What is the biggest documented cave spider and are they aggressive? Thanks for the flashback.