Psammogorgia gracilis Verrill, 1868

Breedy, Odalisca & Guzman, Hector M., 2020, A revision of the genus Psammogorgia Verrill, 1868 (Cnidaria, Anthozoa, Octocorallia) in the tropical eastern Pacific Ocean, ZooKeys 961, pp. 1-30 : 1

Psammogorgia gracilis Verrill, 1868 Figures 12 , 13

Psammogorgia gracilis Verrill, 1868b: 417-418; Kükenthal 1919: 238; Kükenthal 1924: 108; Breedy & Guzman 2011: 29.

Heterogorgia gracilis Harden, 1979: 112-113.

Type material.

Lectotype (designated herein): YPM 813a, dry, Pearl Islands, Panamá, F.H. Bradley, 1866-1867, no additional data.

Paralectotype: YPM 813b, dry small fragment, same data as the lectotype.

Type locality.

Pearl Islands, Panamá.

Diagnosis.

Colonies red, tall, flabelliform, branches subparallel and elongated. Stem a few centimetres long. Calyces close together and all around the branches. Calyces slightly raised and swollen with concentration of wart-clubs up to 0.25 mm long, and acute spindles around the calyx rim. Coenenchymal sclerites: irregular spindles with acute or bifurcated ends up to 0.20 mm long; warty and irregular radiates and some crosses. Anthocodial spindles up to 0.24 mm long in collaret and points arrangements. Sclerites red and orange or of lighter hues.

Description.

The lectotype colony is red and 10 cm long and ~ 6 cm wide. Branching is irregularly dichotomous. The holdfast is absent. The branches emerge at angles of 45-90°, ascend parallel and slightly curve. The main branch of the colony is 2.5 mm in diameter subdividing into long, slender, ascending branchlets, 1.5-1.6 mm in diameter. Branches are round, slender, some extending up to 6.3 cm, undivided or bifurcating at the ends. Branches subdivide up to nine times while terminal branchlets are up to 60 mm long with rounded slightly tapered tips. (Fig. 12A ). The calyces are densely arranged around the branches, slightly raised, swollen and are around 0.3 mm tall and 1 mm in diameter (Fig. 12B ). The calyces have wart-clubs and some irregular spindles around the calyx rim and the base of the anthocodiae. Coenenchymal sclerites are red, orange or of lighter hues (Fig. 12A-C ); including slim spindles with acute ends that may bifurcate (Figs 12C , 13A ). Spindles are 0.12-0.24 mm long and 0.04-0.07 mm wide. Wart-clubs are 0.11-0.25 mm long and 0.04-0.08 mm wide at the expanded head (Fig. 13B ). Warty radiates and crosses are 0.08-0.10 mm long and 0.055-0.07 mm wide (Fig. 13C ); and some warty crosses up to 0.10 mm by 0.09 mm. Anthocodial armature is well developed with orange and pale yellow spiny spindles arranged in collaret and points (Fig. 12A-C ), measuring 0.11-0.20 mm long and 0.03-0.04 mm wide (Fig. 13D ) and flat spindles with small tubercles and scattered warts.

Remarks and comparison.

This species differs from the others by having long, slender and ascending branchlets, which are thinner than in the other species of the genus (Table 1 ). Verrill (1868b) pointed out the abundance of wart-clubs in this species when compared to P. arbuscula and P. teres . According to Verrill, the specimen he described was slender, flabelliform with subparallel and elongated branchlets, measuring12.7 cm long and 10.2 cm wide. The material left (YPM 813a) matches Verrill´s description and illustration. Therefore, we designate this specimen, YPM 813a, as the lectotype of P. gracilis .

Distribution.

Tropical eastern Pacific: only recorded at the type locality Pearl Islands, Panamá.

Figures

Figure 12. Psammogorgia gracilis Verrill, 1868. YPM 813 a A colony B detail of branches showing a tumor C coenenchymal and anthocodial sclerites.

Figure 13. Psammogorgia gracilis Verrill, 1868. YPM 813 a A spindles B wart clubs C radiates D anthocodial spindles.