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Pond Creatures

When Son meets Thalassius

When your son who is a dedicated Koi enthusiast and always assisting you is arachnophobic, you can expect some action when, while maintaining a koi pond, Pieter Junior comes face to face with Thalassius.......... 

The sequence of events are clearly illustrated


Pieter Jnr remove some debris from the pump chamber


Some action - world record bacward jump

The reason....... Fishing spider!


The Fishing spiders belong to the genus Thalassius, a group of large to very large spiders (15 to 30 mm). Thalassius is very variable in colour, ranging from olive brown without markings or reddish to dark brown with the typical cream lateral bands or cream speckling and no banding with various colour forms occurring in the same species in the same locality. Thalassius is very common in KwaZulu Natal and is always associated with water and appears to be both diurnal and nocturnal often retreating amongst vegetation by day. It can be seen resting on the water surface waiting for prey with its hind legs anchored on a leaf or rock or with its entire body on the water anchored to the shore with only a silk thread. The surface tension of the water prevents the spider from sinking. When it detects vibrations of passing prey such as fish, tadpoles, frogs and other invertebrates, it dives into the water and after much splashing the spider emerges from its wrestling match with its prey held under its body. It then retreats to a quiet spot in the vegetation or on a rock to consume its prey. These spiders can be voracious feeders as one was seen to consume two Rana tadpoles, both larger than the spider, within 24 hours.
Thalassius means body covering. It has a waxy coating that allows it to remain dry.

Spare a thought for Pieter Junior. These spiders love pond filters!

Last Updated on Wednesday, 25 August 2010 16:12