Oedothorax gibbosus is widespread across much of the British Isles, inhabiting damp areas such as bogs and fens. The species is unusual in having two distinct variants of the male. Oedothorax gibbosus and O. gibbosus f. tuberosus. The latter was at one time considered a different species, O. tuberosus, but has for many years been considered to be a dimorphic variant of O. gibbosus. The differences in appearance are to do with the shape of the male carapace and can be clearly seen in the micrographs.
Head and chelicerae of a male Oedothorax gibbosus. Note the lobe behind the eyes, and the hairy area between the eyes and the lobe.
Lateral view of the carapace of a male Oedothorax gibbosus
Dorsal view of the carapace of a male Oedothorax gibbosus
Head and chelicerae of male Oedothorax gibbosus f. tuberosus. Note the absence of a lobe or hairy area.
Lateral view of the carapace of a male Oedothorax gibbosus f. tuberosus
Dorsal view of the carapace of a male Oedothorax gibbosus f. tuberosus
Spinnerets of a male Oedothorax gibbosus
Lateral view of the carapace of a female Oedothorax gibbosus. There is no equivalent dimorphism in the female.
Dorsal view of the carapace of a female Oedothorax gibbosus
Pedipalp of a male Oedothorax gibbosus
Pedipalp of a male Oedothorax gibbosus f. tuberosus. There are no obvious differences in structure between this, and that for Oedothorax gibbosus
Epigyne of a (female) Oedothorax gibbosus
Tarsal claw of a male Oedothorax gibbosus
Pedipalp of a female Oedothorax gibbosus. The single claw (arrowed) is barely visible among the large sensory hairs.
