Insularorchestia ashmoleorum (Stock 1996) Lowry & Myers 2022
- Dataset
- Platorchestiinae subfam. nov. (Amphipoda, Senticaudata, Talitridae) with the description of three new genera and four new species
- Rank
- SPECIES
- Published in
- Lowry, J. K., Myers, A. A. (2022): Platorchestiinae subfam. nov. (Amphipoda, Senticaudata, Talitridae) with the description of three new genera and four new species. Zootaxa 5100 (1): 1-53, DOI: 10.11646/zootaxa.5100.1.1
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Malacostraca
- order
- Amphipoda
- family
- Talitridae
- genus
- Insularorchestia
- species
- Insularorchestia ashmoleorum
description
(Fig. 10)
diagnosis
Diagnosis (male). Based on Stock (1996). Gnathopod 1 simplidactylate. Gnathopod 2 propodus palm evenly rounded, without proximal sinus; dactylus short, recurved distally with slight posterior projection near dactylar hinge. Pereopod 7 not incrassate; propodus broad; length 6.6 × width. Uropod 1 endopod with marginal robust setae in 2 rows.
discussion
Remarks. Insularorchestia ashmoleorum exhibits a homoplasy with Platorchestia ano in which the distal end of the gnathopod 2 dactylus is distinctively shortened and recurved. The simplidactylate dactylus on male gnathopod 1 distinguishes it from these species. Like Morinoia, I. ashmoleorum has no sexual dimorphism in P 7, but Morinoia does not have an incrassate A 2.
distribution
Distribution. South Atlantic Ocean. St. Helena (Stock 1996).
materials_examined
Type locality. Broad Gut, near junction with Gates of Chaos, St Helena Island, South Atlantic Ocean (50 ° 59 ’ 59.84 ’’ S 5 ° 44 ’ 00.07 ’’ W). Ecological type. Land-hopper, often near freshwater streams. Habitat. Semi-terrestrial. Freshwater streams. According to Stock, (1996) Insularorchestia ashmoleorum ‘ has been encountered only along small guts (= streams) in the dry and hot lowland zone (altitudes 1 – 40 m) and close to the sea (at 300 – 750 m in direct line). The gut water in these areas is often slightly salty, not so much through marine influence, as by salts dissolved after rains from the volcanic rocks and sediments. The two talitrid species were never found together’. Size. Male, 9.2 – 10 mm, female, 8.5 mm.