Lorne - Point Grey;31 - Nemertea;BQDAC0010;MRG933-12;Tetrastemma sp. SMSA024;SMSA024;SP02365;AN022438;NMVF290417;PID0250713
Species ID
OC-SP-0002969
Discovered
Phylum
Nemertea
Species ID
OC-SP-0002969
Provisional Species Name
Tetrastemma sp_SMSA024
Lowest Valid Taxon Name in WoRMS
Tetrastemma
Lowest Known Rank
Genus
Status
Discovered
Does the taxonomist(s) intend to work on this material further?
3. I/We are not sure yet. This is of course no problem, we will display your species info (if not embargoed) while you work out your species description plan.
Embargo
No
Kingdom
Animalia
Phylum
Nemertea
Class
Hoplonemertea
Order
Monostilifera
Family
Tetrastemmatidae
Genus
Tetrastemma
Date Identified
23/01/2026
Taxonomic Remarks
Worldwide, there are many species of Tetrastemma with similar color and dark band across the first pair of eyes, and similarly truncated stylet basis (e.g. see Maslakova et al. 2025 https://peerj.com/articles/19438/) so differentiation is difficult. So far in southeastern Australia only one species is known with this color pattern, so identification is easy - but this should always be confirmed by COI sequence data. A similar species is described from Western Australia in a different genus - Ammonemertes erseusi Gibson, 1990. There are no sequences of Ammonemertes erseui available for comparison and this species is rare in South Australia in suitable habitat, suggesting that this is the western-most extent of the range for Tetrastemma sp. SMSA024.
Received All Minimal Data for Discovery
08/04/2026
Description of Material
Body 4 – 9 mm long, 0.4 – 0.9 mm wide. Background colour cream. Cephalic lobe wider than neck, diamond shaped, 1.5 times longer than it is wide, separated from body by indistinct neck furrow. Oblique cerebral organ furrows visible dorsally and ventrally. Two pairs of ocelli, the anterior pair covered with a narrow transverse light orange to dark brown band. Posterior tip bluntly pointed to rounded. Rhynchocoel extends to near posterior tip of body. Stylet basis skirted, slightly constricted proximally to its truncated distal end. S/B = 0.6. Two accessory stylet sacs with 2 stylets in each.
Ecology
Usually found in coralline algae but also around rhizoids of other seaweeds or in sediments in the intertidal zone.
Distribution
Flat Rocks to Bridgewater Bay, Victoria, Ausrtalia, where it is common. Also rare in the South Australian Gulfs, South Australia, Australia.
Scientific Name Authorship
Maslakova, Svetlana
Lorne - Point Grey;31 - Nemertea;BQDAC0010;MRG933-12;Tetrastemma sp. SMSA024;SMSA024;SP02365;AN022438;NMVF290417;PID0250713
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