Halammohydra joergerae, Tödter & Worsaae & Schmidt-Rhaesa, 2023

Tödter, Lenke, Worsaae, Katrine & Schmidt-Rhaesa, Andreas, 2023, Comparative molecular and morphological species delineation of Halammohydra Remane, 1927 (Hydrozoa) - with the description of four new species, Organisms Diversity & Evolution (New York, N. Y.) 23 (3), pp. 455-476 : 466-467

Halammohydra joergerae n. sp

Zoobank: urn:lsid:zoobank.org:act:D83A943A-EB86-49B9-9C09-01C68E93CE72 .

Etymology this species is dedicated to Katharina Jörger for organizing of the summer school (“Meiozores 2019”) on the Azores.

Material examined “ Riberinha” on the island Sao Miguel (Azores), Portugal, 22 Jul 2019, medium coarse sand, K. Jörger and F. Goetz. Images taken with a compound microscope and 18S and CO1 sequences of the holotype obtained. Entire specimens used for DNA extraction, frozen DNA solutions deposited in the Museum of Nature–Zoology in Hamburg (LIB, Biobank) under Sample ID A17 (holotype) .

Description of the holotype ovoid gastric tube, square mouth opening, adhesive behavior, and cylindrical aboral cone. 12 tentacles, equally distributed in both whorls (6 + 6), slender tentacles and subaboral ones with unequal lengths and irregular surface. No long tentacles. Statocysts 6.

Remarks all 13 specimens are from the station “Riberinha” on the Azores ( Table 3) and form a cluster, which is well supported by phylogenetic analyses and all species delimitation tests, except for 18S in ABGD ( Fig. 1 , SI 2). In this group, morphological characters varying are the body size, aboral cone, number of tentacles and statocysts, and tentacle bases. The gastric tube measures 348 ± 117 µm (n = 5) in length (Fig. 4e). Whenever the aboral cone was visible, it had a conical or cylindrical shape and a cup-shaped adhesive organ reaching in half of the depth of the aboral cone. The tentacle number ranges from 10 to 14, and they are equally distributed in the two whorls. Some specimens have a club-shaped base in the subaboral whorl, but most have no thickening. Statocysts are 5 or 6 ( Table 4).

Figures

Fig. 1 Phylogenetic tree of all three genes concatenated with support values of BI/ML (posterior probability/bootstrap value). Nodes with an * have a support of 100/100. Some clusters are collapsed. Sum-