1988] 
Sierwald — Thalassius spinosissmus 
247 
opisthosorna. The male then spun broad threads around the 
female’s patellae (Fig. 2). To insert the embolus, the male reached 
under the female’s opisthosorna with the right or left palp along the 
female’s right or left side, respectively (Fig. 3). 
The males expanded the bulb in front of the epigynum (Fig. 4); 
insertions lasted five to twenty seconds for each bulb. In ten out of 
twelve copulations both bulbs were used alternately, three to five 
insertions occured during copulations. After copulation, the male 
left the fastened, inactive female. Females began to remove the 
threads around the patellae two to seven minutes after copulation. 
Males and females of spinosissimus were able to mate more than 
once either with the same or with other mates (three males and two 
females were used twice for matings). 
Parental care 
Egg laying and cocoon building were not observed. The cocoons 
are round and whitish and carried by the female in the chelicerae 
under the prosoma. Between 150 and 200 spiderlings hatched after 
19-21 days (at 20° to 25° C) from each of 7 cocoons observed in the 
laboratory. Shortly before hatching, the females spun an irregular 
nursery-web and fastened the cocoon in its center. The spiderlings 
remained in the nursery-web for up to six days; they tended to stay 
in a central cluster, spinning additional threads. The females 
remained almost inactive at the edge of the web (Fig. 5). Without 
molting, the spiderlings began to disperse and moved to the upper 
corners of the laboratory windows. 
Discussion 
The copulatory position of T. spinosissimus agrees with that of 
other hunting spiders (Gerhardt & Kastner 1937/38: 547; type three 
in Foelix 1982: 194). The same position is described for Dolomedes 
fimbriatus (Clerck, 1758) by Gerhardt (1926: 7). Spinning threads 
around the females legs by the males prior to copulation has been 
observed in Pisaurina mira (Bruce & Carico 1986). 
The parental care as displayed by T. spinosissimus occurs in other 
Pisauridae as well: Pisaura and Dolomedes (Gerhardt & Kastner 
1937), Afropisauria (Blandin 1979: 82), Pisaurina (Carico 1972: 
303), Tinus (Carico 1976: 301), Megadolomedes (Davies & Raven 
1980: 139) and Architis (Nentwig 1985: 301). The results obtained 
