Aphanipathes puertoricoensis

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. 2 A) 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.

Description of holotype. The holotype (USNM 1660436) is a fragment from the whole colony (Fig. 2 A) that is 0.35 m tall and includes a first order and two second order branches (Fig. 2 B). 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. 3 A, B). 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. 3 B). Polypar spines have a distal angle of about 75 ° and abpolypar spines have a distal angle of about 45 ° (Fig. 3 A, B). 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. 3 B). 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. 3 C, D). Between the tubercles faint striations can be observed (Fig. 3 C) and sometimes slight papillae or immature tubercles (Fig. 3 D). 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. 2 F). There is no notable difference in the size of the sagittal and lateral tentacles based on preserved material.

Figs 1, 2, 3, 4

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.

Distribution. Known only from Guayanilla Canyon, Puerto Rico, Caribbean Sea; 357 m depth.

Etymology. The species name " Aphanipathes puertoricoensis " is based on the type locality.

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.