Cuniculomaera Tandberg & Jażdżewska, 2024

(SOSA), Senckenberg Ocean Species Alliance, Brandt, Angelika, Chen, Chong, Engel, Laura, Esquete, Patricia, Horton, Tammy, Jażdżewska, Anna M., Johannsen, Nele, Kaiser, Stefanie, Kihara, Terue C., Knauber, Henry, Kniesz, Katharina, Landschoff, Jannes, Lörz, Anne-Nina, Machado, Fabrizio M., Martínez-Muñoz, Carlos A., Riehl, Torben, Serpell-Stevens, Amanda, Sigwart, Julia D., Tandberg, Anne Helene S., Tato, Ramiro, Tsuda, Miwako, Vončina, Katarzyna, Watanabe, Hiromi K., Wenz, Christian & Williams, Jason D., 2024, Ocean Species Discoveries 1 – 12 — A primer for accelerating marine invertebrate taxonomy, Biodiversity Data Journal 12, pp. e 128431-e 128431 : e128431-

Cuniculomaera Tandberg & Jażdżewska gen. nov.

Composition: One valid species, which is described herein; Cuniculomaera grata Tandberg & Jażdżewska , sp. nov.

Cuniculomaera grata Tandberg & Jażdżewska. Type species.

Diagnosis

Small round eyes. Accessory flagellum 8 - articulate. Pereopod 2 propodus suboval, palmar corner not sharply defined, dactylus smooth and sharp. Epimeral plates smooth, epimeral plate 3 with sharp tooth. Uropod 3 elongate, rami of similar length, covered by bushy setae. Telson deeply and widely cleft.

Etymology

Cuniculomaera is a compound noun formed from the Latin second-declension noun cuniculus (burrow) and the suffix - maera from Maera , the type genus of the family Maeridae . Gender: feminine.

Taxon discussion

The decision to erect a new genus for Cuniculomaera grata Tandberg & Jażdżewska , sp. nov. (described below) comes from it differing in diagnostic characters from all initially eligible genera within the family Maeridae Krapp-Schickel, 2008 . The placement of the genus into Maeridae follows the discussion in Krapp-Schickel (2008), where she separates the Ceradocus - Elasmopus - Maera - group from Melitidae Bousfield, 1973 , based on the equiramous uropod 3 in this group compared with the parviramous uropod 3 in Melitidae . The use of the defining morphological characters of uropod 3 is kept by Lowry and Myers (2013), who also keeps Maeridae separate from the morphologically quite similar Hadziidae S. Karaman, 1943 due to the morphology of the gills. It should also be noted that Hadziidae are exclusively freshwater species. The gills of Cuniculomaera grata sp. nov. are not stalked (rather “ normal ” for marine species), again placing the new genus within Maeridae .

The equiramous uropod 3 of Cuniculomaera gen. nov. can be observed in Fig. 14 . Sadly, uropod 3 was lost in the specimen that was sampled. Placing it in the Maera Leach, 1814 s. l. group (sensu Krapp-Schickel 2008) comes from it differing from Ceradocus A. Costa, 1853 in its epimeral plate 3 not being serrated (it is smooth, with a clear tooth), the shape of the telson (the lobes being slender and with two small teeth compared to the one tip on each lobe “ Ceradocus - telson ”) and the dorsal shape of the urosome which is smooth compared to the “ can have teeth ” of Ceradocus . It differs from Elasmopus A. Costa, 1853 by having a long accessory flagellum (not short as for Elasmopus ) and in the shape of the mandibular palp article 3 (the Elasmopus article is falcate, Cuniculomaera has this palp straight) and epimeral plate 3 posterior corner being a sharp tooth compared to the Elasmopus blunt corner.

Maera s. l. was split into several genera by Krapp-Schickel (2008); the present new genus can be separated from these by the combination of the accessory flagellum, eye-shape, pereopods 1 and 2 shapes, epimeral plate 3 posterior corner and telson-shapes. It also differs in its depth range, albeit this is not a diagnostic character.

The obtained sequence was positively checked as belonging to Amphipoda against the Barcode of Life Data System ( BOLD) and GenBank databases; however, with only ca. 80 % similarity to published sequences. The closest relative in GenBank was Uristes gigas Dana, 1852 (78.97 % similarity, acc. No. MH 825809.1) while in BOLD: Wimvadocus torelli (Goës, 1866) (79.97 %, sample ID: BSM 08 T 16-01, record not available in GenBank). The number of publicly available sequences of Maeridae is relatively low (164 sequences of which 62 belong to only two species), while the family is represented by 423 species grouped in 48 genera ( Horton et al. 2023). A phylogenetic analysis was not conducted; only the barcode of the new species is provided for future use.

Figures

Figure 14. Burrows where Cuniculomaera grata Tandberg & Jażdżewska, sp. nov. is suggested to live. Photos from AleutBio expedition. A. Amphipod in last of burrow openings; B. Zoom in of amphipod from A.