Aphanipathes puertoricoensis Horowitz & Quattrini, 2023

Horowitz, Jeremy, Opresko, Dennis M., Gonzalez-Garcia, Maria del P. & Quattrini, Andrea M., 2023, Description of a new species of black coral in the family Aphanipathidae (Anthozoa, Antipatharia) from Puerto Rico, ZooKeys 1173, pp. 97-110 : 97

publication ID	https://dx.doi.org/10.3897/zookeys.1173.104141
publication LSID	lsid:zoobank.org:pub:F981A3C1-577D-42A1-91AD-6C938E0C16B0
persistent identifier	https://treatment.plazi.org/id/5AD4DED2-215F-4BC5-AB58-2739FD4D0183
taxon LSID	lsid:zoobank.org:act:5AD4DED2-215F-4BC5-AB58-2739FD4D0183
treatment provided by	ZooKeys by Pensoft
scientific name	Aphanipathes puertoricoensis Horowitz & Quattrini
status	sp. nov.

Treatment

Aphanipathes puertoricoensis Horowitz & Quattrini sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4

Material examined.

Holotype: USNM 1660436 (USNM SEM stubs 530-532), Guayanilla Canyon , off Puerto Rico, station GEX-22-04, 17°54'17.80"N, 66°43'18.78"W, NOAA Ship Nancy Foster , Expedition : Illuminating Pelagic and Benthic Biodiversity in Deep Waters of Puerto Rico, 357 m depth, coll. A.M. Quattrini, A.G. Collins & E.E. Cordes, 12 April 2022. GoogleMaps

Type locality.

Guayanilla Canyon, Puerto Rico, Caribbean Sea, 357 m depth.

Diagnosis.

Tall, sparsely branched colony with two and rarely three orders of branches. Stem 0.2 m tall, first order branches over 1 m long, distally slightly curved or coiled, and arranged irregularly around stem; second order branches short and sparsely occurring; third order branches rare. Distal branch angles usually close to 90°. Spines form a distinct quincunx pattern with six axial rows of spines counted in one view. Polypar spines up to 0.5 mm tall, possess 20 to 40 or more small conical tubercles visible in lateral view that extend from the tip halfway to the base. Abpolypar spines up to 0.32 mm tall, possess 10 to 20 small conical tubercles visible in lateral view that extend from the tip halfway to the base. Polypar and abpolypar spines spaced 0.47 to 0.57 mm apart with three spines per mm in each row. Polyps 1.1 to 1.6 mm in diameter, arranged in a single series, with six to eight polyps per cm.

Description of holotype.

The holotype (USNM 1660436) is a fragment from the whole colony (Fig. 2A View Figure 2 ) that is 0.35 m tall and includes a first order and two second order branches (Fig. 2B View Figure 2 ). The diameter near the base of the second order branch is about 1 mm including spines.

The spines are laterally compressed and arranged in a quincunx pattern with five to six longitudinal rows in one view and three spines per cm counted in one longitudinal row (Fig. 3A, B View Figure 3 ). On a section of branch 0.3 mm in diameter, the polypar spines are about 0.35 mm tall and the abpolypar spines are 0.16 mm tall. On a section of a branch 0.45 mm in diameter the polypar spines are about 0.5 to 0.6 mm tall and the abpolypar spines are about 0.32 mm tall (Fig. 3B View Figure 3 ). Polypar spines have a distal angle of about 75° and abpolypar spines have a distal angle of about 45° (Fig. 3A, B View Figure 3 ). The spines have conical tubercles on their surface extending from the apex to about midway down the spine towards the base. Based on counts made on one lateral side of a spine and including those seen on the distal and proximal edges, most polypar spines have between 20 to 40 small conical tubercles while the abpolypar spines have about half as many tubercles (Fig. 3B View Figure 3 ). The conical tubercles are 0.007 mm tall and run at right angles to the direction of the spine. Within these rows about three tubercles can be counted over a 0.1 mm distance (Fig. 3C, D View Figure 3 ). Between the tubercles faint striations can be observed (Fig. 3C View Figure 3 ) and sometimes slight papillae or immature tubercles (Fig. 3D View Figure 3 ).

The polyps are arranged in a single row. In the preserved state the polyps are 1.1-1.6 mm in transverse diameter with an interpolypar space of about 0.15 mm, and there are six to eight polyps per cm (Fig. 2F View Figure 2 ). There is no notable difference in the size of the sagittal and lateral tentacles based on preserved material.

Description of colony from which holotype was collected.

The colony from which the holotype was collected was videotaped in situ and based on a screen shot from that video (Fig. 2A View Figure 2 ) the complete colony is approximated to be over 1 m tall and over 2 m wide including branches. The main stem is approximated to be 0.2 m tall and consists of approximately eight irregular rows of primary branches, spaced about 2 cm apart in a row. Primary branches are long and loosely coiled at their distal end, reaching lengths of over 1 m. Secondary branches are sparse and third order branches are rare.

Phylogenetic results.

We obtained between 2 to 15 million PE reads per specimen, which assembled into 54,513 to 287,021 contigs. The new Aphanipathes species had 5,400,183 reads and 262,434 assembled contigs. From the contigs, 1186 to 1609 UCE and exon loci were obtained per specimen. The 60% taxon-occupancy matrix included 793 loci that were concatenated into an alignment with a total length of 365,565 bp. Read and locus summary statistics are detailed in Suppl. material 2. The phylogeny (Fig. 4 View Figure 4 ) was strongly supported, with 100% bootstrap and Sh-alrt values at every node but one. In addition, the topology is congruent with the phylogeny presented in Horowitz et al. (2022) and Opresko et al. (2021).

Based on specimens included, phylogenetic results place the new species sister to two specimens that most closely resemble Aphanipathes pedata (Gray, 1857) from 229 m depth in the Gulf of Mexico (USNM 1288458) and 155 m depth from the Caribbean Sea (USNM 1410008) (Fig. 4 View Figure 4 ). Unfortunately, both specimens are incomplete colonies, we lack molecular data for the A. pedata holotype, and spine comparisons are based on just one SEM of the holotype (Fig. 3E View Figure 3 ). For these reasons, we conservatively identify these two specimens as A. cf. pedata . We also lack molecular data for the type of the genus, A. sarothamnoides , which will be useful when reviewing the taxonomy of the genus.

Comparative diagnosis.

The new species has morphological features that fit the emended diagnosis of Aphanipathes , including a branched corallum, polypar spines being twice as tall as abpolypar spines, pronounced tubercles on skeletal spines, and small polyps between 1 and 2 mm in transverse diameter, reaching a density of eight polyps per cm. In addition to phylogenetic affinity, the new species shares a high density of tubercles on the surfaces of spines, being greater than 20 counting all tubercles on the visible side of a spine, and similar sized polyps with A. pedata (Fig. 3E View Figure 3 ). However, the new species is different from A. pedata by having three-dimensional branching ( A. pedata has branches arranged uniserially, forming fronds, larger terminal branchlets (> 20 cm vs 10 cm), wider terminal branchlet distal angles (90° vs 30-45°), and lower branch complexity (two vs eight or more orders of branches) (Fig. 2A-C View Figure 2 ). The new species also has tubercles that only extend midway down the spine and are generally less pronounced (Fig. 3B View Figure 3 ) compared to A. pedata , which has more pronounced tubercles present from the tip down to the bottom third or almost to the base of each spine (Fig. 3E, F View Figure 3 ). The new species also has spines that are distinctly thinner on their distal ends compared to the type of A. pedata and two A. cf. pedata specimens (Fig. 3A, B View Figure 3 and Fig. 3E, F View Figure 3 ).

The new species is also different from the other species in Aphanipathes by having longer terminal branchlets (> 20 cm vs 10 cm or less), wider terminal branchlet distal angles (90° vs 30-60°), and is mostly branched to the second order compared to three or more orders in A. sarothamnoides (Fig. 2E View Figure 2 ), as many as six orders in A. salix and A. flailum , and ten or more orders in A. verticillata .

The new species has a branching pattern that is like Anozopathes Opresko & Bo, 2021 (Fig. 2D View Figure 2 ). However, the new species is a much larger colony compared to other Anozopathes due to branch lengths> 1 m vs max 0.18 m long, resulting in approximate colony widths and heights of 2 m (Fig. 2A View Figure 2 ) vs 0.16 m in Anozopathes palauensis Opresko & Brugler, 2021 (Fig. 2D View Figure 2 ) and 0.36 m in Anozopathes hawaiiensis Opresko & Bo, 2021. The new species also possesses a greater abundance of conical tubercles on the spines compared to Anozopathes (20-40 vs six to eight). Lastly, the new species has smaller polyps than Anozopathes (about 1.3 vs 2 mm in Ano. palauensis and 3.6 mm in Ano. hawaiiensis ) and greater polyp density per cm (6-8 vs 3-5 in Ano. palauensis and 4-5 mm in Ano. hawaiiensis ) (Fig. 2F, G View Figure 2 ).