(animals) > Bilateria > Ecdysozoa > Panarthropoda > Tritocerebra >
Arthropoda > Arachnomorpha > Cheliceriformes > Chelicerata > Euchelicerata
> Arachnida > Araneae
This orb-weaving family was previously included in the
family Araneidae but was separated due to certain morphological differences and
the way in which they capture and consume their prey. The Tetragnathidae is a
small family comprising 5 genera in South Africa and includes both diurnal and
nocturnal species ranging in length from 5-15 mm. They pose no threat to man.
It has an enormous pair of forward projecting chelicerae
armed with numerous cheliceral teeth (projections), which are exaggerated in the
males. This helps them restrain the female's jaws to facilitate mating.
Tetragnathids are cryptically coloured in shades of brown
and cream and green for those species that occur amongst foliage. Unlike the
Araneidae family which first wraps its prey
in silk after capture and then bites it, Tetragnathidae and
Nephilids first bite and then wrap, the
prey being crushed by the force of their large fangs.
Until recently Clitaetra, Nephila, Nephilengys and
Leucage belonged to this family but have now reverted to the
The web is usually horizontally inclined over streams or
bodies of water in sunlit areas. It is taken down and reconstructed daily and
the spider is often found on an incomplete web. On the web the spider resembles
a piece of dry grass as the front two pairs of legs are projected forward while
the back pairs are projected backwards.
Genera indigenous to southern Africa
This genus occurs in South America, China to Japan, Madagascar and only
Diphya simoni in South Africa.
Meta (thick-jawed water spider)
Meta is a
nocturnal genus that occurs in cool moist areas. One named species, Meta
meruensis, is recorded from South Africa. A second unidentified species,
from the Cape Peninsula, is found hanging suspended below the web, which is
positioned close to the ground among rocks, or vegetation in small
(100-200mm) horizontal orb-webs in heavily shaded, forested areas. It is a
robust spider with a globose (round) abdomen with downward projecting
chelicerae. The integument (body covering) is decorated in brown and coppery
colours, the legs are banded and decorated with numerous spines. This may be
a new species and is the nocturnal equivalent of Tetragnatha that
occurs in sunlit situations. There may be a further species from the
Langeberg in the Western Cape. Meta is Latin for "conical" or "pear
shaped" referring to the abdomen.
Pachygnatha (thick-jawed water spider)
species are reported to be web-bound as juveniles but on maturing, leave the
web and become free ranging. Pachygnatha zappa is the only species recorded
from South Africa. It has a body length of 4mm and occurs from Limpopo
Province to equatorial Africa. The chelicerae is similar to Tetragnatha but
is bulky and projects downwards. Pachygnatha is derived from the Greek
"pachy" means "thick" and "gnathos" means "jaws".
Tetragnatha (long-jawed water spiders)
Tetragnatha is a nocturnal and sometimes diurnal
spider. The integument is cryptically coloured in shades of brown, cream and
green for those species that occur amongst foliage. Tetragnatha has
an very elongated body. The long chelicerae projects forward with long fangs
folded against it. The delicate orb-web, with few radii and spirals, is
usually horizontally inclined over streams or bodies of water. The web is
taken down and reconstructed daily and the spider is often found on an
incomplete web. On the web the spider resembles a piece of dry grass as the
front two pairs of legs are projected forward while the back pairs are
projected backwards. Tetragnatha has a world distribution and is the
most common genus, of the Tetragnathidae, with 14 species in South Africa.
The name is derived from the Greek "tetra" means "four" and "gnathos" means