Anozopathes, Opresko & Bo & Stein & Evankow & Distel & Brugler, 2021

Opresko, Dennis M., Bo, Marzia, Stein, David P., Evankow, Ann, Distel, Daniel L. & Brugler, Mercer R., 2021, Description of two new genera and two new species of antipatharian corals in the family Aphanipathidae (Cnidaria: Anthozoa: Antipatharia), Zootaxa 4966 (2), pp. 161-174 : 162-164

Genus Anozopathes gen. nov. Opresko & Bo

Diagnosis. Colonies relatively small, generally not more than about 25 cm tall, very sparsely branched usually only to the second order, but possibly up to the fourth order, with long branches disposed on all sides of the stem and lower-order branches. Branch angles usually very wide, 90º or greater. Spines conical in lateral view, laterally compressed, acute; with scattered tubercles on their surface, usually near the apex. Tubercles predominantly on the polypar spines, Polyps up to 3.6 mm in transverse diameter, and arranged in a single row.

Type species. Anozopathes hawaiiensis sp. nov.

Remarks. A sample of the holotype of the type species, Anozopathes hawaiiensis sp. nov., as well as the holotype of Anozopathes palauensis sp. nov. (see below) were included in a DNA sequencing study using mitochondrial nad5 -IGR- nad1 ( Chery et al. 2018; digital poster presentation available upon request to MRB) and the results showed that both species grouped within the family Aphanipathidae ( Fig. 1 ). On the basis of the growth form of the corallum, the genus is intermediate between densely branched morphotypes in the genus Aphanipathes and the new aphanipathid genus Aphanostichopathes (see below) comprised of species previously assigned to the genus Stichopathes , and represented by Aphanostichopathes cf. dissimilis Roule, 1902, 1905 , in Figure 1 (Note: Aphanostichopathes cf. dissimilis was originally presented in Chery et al. as Stichopathes dissimilis ; however, examination of the SEMs of the spines of the type specimen of S. dissimilis indicate that it may not be conspecific with Roule’s species). Based on K2P genetic distance estimates for nad5 -IGR- nad1, the two species of Anozopathes are genetically much closer to the Aphanostichopathes cf. dissimilis (with genetic distances of 0.0021 –0.0044) than to the Aphanipathes / Phanopathes clade (genetic distances 0.1736 –0.1966) in Figure 1 . Both Anozopathes species are genetically identical using the nad5 -IGR- nad1 region; however, this gene region does not have the same power to resolve species as the cox3 -IGR- cox1 region (which was not successfully sequenced). Note: the species identified as Stichopathes cf. flagellum in Fig. 1 has faint morphological features indicating that it might also belong in the family Aphanipathidae ; however, the fact that it groups with a morphologically unrelated aphanipathid genus, Acanthopathes , requires further study.

Several previously described genera were also based on species forming sparsely branched colonies. Brook (1889) created the genus Pteropathes for a branched species ( P. fragilis ; holotype NHMUK 90.4.9.9) with long straight branches, many of which have a very narrow distal branch angle. In addition, some of the branches (up to five in a row) are arranged uniserially. Based on Brook’s illustration, the polypar spines are estimated to be up to 0.54 mm tall and appear to be smooth, without tubercles. The polyps are arranged in a single row, and are 2–3 mm in transverse diameter (4–5 per cm with very little coenenchyme between adjacent ones). The uniserial branching and the narrow distal branch angles suggest that Pteropathes might be related to species of Antipathes or Aphanipathes . The very large spines are more typical of some species of Aphanipathes . The spines need to be re-examined more closely with an SEM to determine if there is evidence of tubercles.

Van Pesch (1914) created the genus Hillopathes for a species ( H. ramosa ) with very sparse branching that he had first thought was a species of Cirrhipathes ( van Pesch, 1910) . As in Cirrhipathes , the polyps in H. ramosa are not arranged uniserially, but are crowded together on one side of the axis giving the appearance that they are in multiple rows. Van Pesch (1914) considered the presence of branches to be a generic level character. The spines in H. ramosa were reported to be up to 0.39 mm in height, and van Pesch thought that this might suggest a relationship to Aphanipathes ; however, the spines were described by van Pesch (1914) as being smooth. The absence of tubercles on the spines does not preclude the genus from being related to the family Aphanipathidae ; however, the non-uniserial arrangement of the polyps would support the conclusion that Hillopathes is not related to Anozopathes . Also, it is quite possible that the specimens of Hillopathes that van Pesch described were actually specimens of Cirrhipathes that had been broken off at the growing tip and then underwent regeneration producing several separate growing tips. Breakage of the apical portions of black coral whips by strong currents is known to be a common occurrence on the reefs of Indonesia ( Bo et al. 2009).

Etymology. The genus name is derived from the Greek “anozos” meaning few or no branches, and the commonly used suffix “ pathes ”.

Figures

FIGURE 1. A maximum likelihood-based phylogenetic tree of the family Aphanipathidae based on mitochondrial nad5-IGRnad1 sequence data (Chery et al. 2018). The original tree consisted of 112 taxa and 682 sites and was rooted internally with the Leiopathidae. PhyML used the GTR+G model of sequence evolution and 1,000 bootstrap replicates.