| Pagurus hemphilli | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Anomura |
| Family: | Paguridae |
| Genus: | Pagurus |
| Species: | P. hemphilli |
| Binomial name | |
| Pagurus hemphilli Benedict, 1895 | |
Pagurus hemphilli is a species of hermit crab in the family Paguridae. It is found in the Eastern Pacific and was described from Monterey, California. [1]
P. hemphilli is a rich maroon color with small blue dots, yellow-tipped dactyls, gold-ringed corneae, and red to orange-red antennae [2] that lack spots or rings. [3] Juveniles sometimes have white bands on their ambulatory legs. The chelipeds ("claws") are dramatically different in size, with the major cheliped being much larger than the minor cheliped. [1] It is almost totally hairless over its entire body and has a smooth, shiny shield. [1] It has a distinct rostrum that is produced well beyond the carapace lateral frontal lobes. [1] The chela palms are rough with visible bumps. [1] The uropods are asymmetrical, and the carapace can measure up to 15 mm. [1]
Its congener Pagurus granosimanus is similar in appearance, [2] with both being dark in color with light dots, [3] but true to its name, P. hemphilli is more maroon than the olive P. granosimanus. [3] and can also be separated from P. granosimanus based on the comparatively longer length of the outer portion of the carapace, even at the juvenile stage. [2] The legs of the two species are also quite different, with P. hemphilli having legs that are dark red with tiny yellow to blue spots and a white dot at the end, whereas P. granosimanus has olive legs with light blue spots. [3]
P. hemphilli ranges along the North American coast from Alaska [4] to the Central Coast of California. [5] [1] It is more common towards the southernmost extent of its range in Central California. [1]
P. hemphilli is found on rocks in shallow water. [6] It mostly occupies the upper subtidal region to a depth of 50 m, but can occur in low intertidal pools. [5] P. hemphilli occupies a deeper zone of the shoreline compared to its congeners, Pagurus samuelis , Pagurus granosimanus , and Pagurus hirsutiusculus . [5] It therefore has a comparatively lower tolerance of warm water, experiencing increased mortality from high water temperature, reportedly 50% mortality at 30.1° C. [5] In the wild, it prefers waters that do not exceed 20° C. [5]
Most commonly, P. hemphilli dwells in the shells of Tegula species [6] , such as Tegula brunnea , Lithopoma species [6] , and Astraea species. [1] To acquire a better shell, P. hemphilli engages in shell fights, [7] with the loser conceding their shell. These shell fights may be intraspecific or with other Pagurus species. [7] In these fights, the larger hermit crab has the advantage. [7]
The shells that this species inhabits are often heavily encrusted with coralline algae and with hitchhikers like the slipper snail Crepidula adunca and the limpet Acmaea mitra . [1] An species of Amphipod in the genus Liljeborgia has been observed residing with this species of hermit crab inside the shell; [8] this commensal occupant remains undescribed. [9]
Pagurus hemphilli is named after Henry Hemphill, an amateur American shell collector, malacologist, and member of the San Diego Society of Natural History. [10]