This small but colourful cribellate spider likes to spin its small webs on shiny-leafed trees or shrubs, such as holly or ivy (or in the case of the specimens I collected on the shiny paint on my front door). Their appearance is distinctive. The male (illustrated) has an orange carapace and green abdomen, while the female is almost entirely green.
Head and chelicerae of a male Nigma walckenaeri.Note the swellings and ridges on the chelicerae, used during mating for the female to hold on to.
Head and chelicerae of a female Nigma walckenaeri to the same scale as the male one.
Left Pedipalp (male sexual organ) of Nigma walckenaeri
Epigyne (female sexual organ) of Nigma walckenaeri
Spinnerets and cribellum of a female Nigma walckenaeri
Cribellum of female Nigma walckenaeri
Cribellum of Nigma walkenaeri at high magnification, showing the individual nozzles that produce the very fine silk.
Spinnerets of a male Nigma Walckenaeri. Note the underdeveloped cribellum.
Tarsus of Nigma Walckenaeri
Calamistrum of Nigma walckenaeri, used to comb out the silk from the cribellum.
Pedipalp of a female Nigma walckenaeri. The single claw (arrowed) can just be made out.