Description: This species was described in 2009 and is only known from a few specimens. It exists as a very thin crust forming patches on boulders, 6–10 cm in maximum diameter. The external appearance is a cream to palish yellow/buff coloured crust, with raised white pore sieves.

Habitat: Records of this species are from lower circalittoral bedrock or boulders in moderately exposed, tide swept sites.

Distribution: So far only known from White Cliffs area, Rathlin Island.

Similar Species: Lissodendoryx jenjonesae and pale coloured Hymedesmia spp. are all quite similar and identification requires examination and comparison of the spicules.

Key Identification Features:

• Identification requires examination of spicules under a compound microscope and careful comparison with other Hymedesmia spp. (Goodwin & Picton, 2009).

iNaturalist: Hymedesmia cohesibacilla at iNaturalist World Species Observations database.

GBIF data for Hymedesmia (Hymedesmia) cohesibacilla

WoRMS: Hymedesmia cohesibacilla at World Register of Marine Species. Accepted name: Hymedesmia (Hymedesmia) cohesibacilla Goodwin & Picton, 2009. AphiaID: 416418.

Classification: Biota; Animalia; Porifera; Demospongiae; Heteroscleromorpha; Poecilosclerida; Hymedesmiidae; Hymedesmia