EDA sp EDA


Family :  Gnaphosidae
New Genus : EDA
New Species :  Gnaphosidae EDA sp EDA

5.5mm

EDA LOGYARD 18-11-2014 TUE 9:45AM
 

Family: Gnaphosidae (Ground Spiders)


Biology: The Gnaphosidae is the seventh largest spider family of the world encompassing ca. 2000 species in 8 subfamilies and 114 genera. They range in size from small to large (2-18 mm body size). The species are free-living found mailnly at ground level in open habitats but some species are house spiders, for example Scotophaeus blackwalli in the northern parts of its distributional range. They build a tubular retreat, from which they leave at night to hunt prey. The female guard her papery egg sack hidden in small holes under logs, stones, etc. Most species are active at night, however spiders of the somewhat atypical genus Micaria are diurnal hunters running rapidly about in bright sunshine.


Characters of family: The gnaphosids are rather stout ecribellate spiders with a flattened and elongate abdomen.

Carapace:
The carapace is ovoid and rather low being smoothly convex and with a distinct fovea (a small depression 凹) at behind.

The head is not sharply set off from the thoracic region. Gnaphosids are fairly easily recognized by their cylindrical and parallel spinners, the anterior pair being slightly longer, and more heavily sclerotized than the posterior pair. The anterior spinners are separated from each other by approximately one spinner diameter with some exceptions, e.g. Micaria in which genus anterior spinners are closer.

 

Eyes:
8 eyes in 2 rows. The posterior medial eyes are not round, but oval, triangularly reduced to slits. All eyes are with a silvery sheen except for the anterior medials, which are dark.  The curvature of the posterior row of eyes and the position and shape of cheliceral lamina and teeth are important characters when keying gnaphosids to genus level under the stereomicroscope.

 

The Mouth Parts:
The sternum is ovoid, pointed posteriorly 向後.
The chelicerae are robust, and the fang are short.
The Maxillae (endites)  are provided with a serrula (row or cluster of tiny teeth on the front margin).
Labium.

 

Gnaphosids are also characterized by having 2 tarsal claws, claw tufts, and scopulae.

Legs:
Legs are NOT stout. This is unusual compared with other species in the same family which usually have stout legs as a ground walking spiders.

 and in some species there are small brushes of more and less stiff hairs present distally on metatarsus IV.

Palp:
Female palp is furnished with small spines and a finely toothed claw.

 

The abdomen is often provided with dense coverage of short sleek hairs giving the abdomen a mousy-like appearance. Sometimes erect, curved setae are present, particularly at the anterior edge (see for example images of Gnaphosa lucifuga). Many species are uniformly coloured in greyish-brown or blackish colours. However, abdomens of some species have striking white patterns of spots or lines while abdomens of others are iridescent. Most males have a scutum at the anterior end. The spiracle is situated close to the spinners. Gnaphosids are entelegyne spiders often having rather large epigynes with sclerotized structures. They are somewhat variable and closely related species may be difficult to identify. Male palps are usually provided with a large tibial apophysis and the shape of this is important when identifying the species.
 


 


Palp:
Female palp is furnished with small spines and a finely toothed claw.

Legs are NOT stout. This is unusual compared with other species in the same family which usually have stout legs as a ground walking spiders.

The Mouth Parts:
The sternum is ovoid, pointed posteriorly 向後.

The chelicerae are robust. Fang are short.

The Maxillae (endites)  are provided with a serrula (row or cluster of tiny teeth on the front margin).

Labium is triangular shape.

 

 


Carapace:
The carapace is ovoid and rather low being smoothly convex and with a distinct fovea 凹 at behind.

Eyes:

8 eyes in 2 rows. The posterior medial eyes are not round, but oval, triangularly reduced to slits. All eyes are with a silvery sheen except for the anterior medials, which are dark.
 


Size:

Body Length : 5.5mm