Peinaleopolynoe orphanae Hatch & Rouse, 2020

Hatch, Avery S., Liew, Haebin, Hourdez, Stephane & Rouse, Greg W., 2020, Hungry scale worms Phylogenetics of Peinaleopolynoe (Polynoidae, Annelida), with four new species, ZooKeys 932, pp. 27-74 : 27

publication ID	https://dx.doi.org/10.3897/zookeys.932.48532
publication LSID	lsid:zoobank.org:pub:7C93908F-F97E-4ABB-BD7E-CD68C38790E9
persistent identifier	https://treatment.plazi.org/id/759AD6A2-7695-42FC-9E33-0EF105A1D97A
taxon LSID	lsid:zoobank.org:act:759AD6A2-7695-42FC-9E33-0EF105A1D97A
treatment provided by	ZooKeys by Pensoft
scientific name	Peinaleopolynoe orphanae Hatch & Rouse
status	sp. nov.

Treatment

Peinaleopolynoe orphanae Hatch & Rouse sp. nov.

Figures 6A-E View Figure 6 , 7A View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10A View Figure 10 , 11 View Figure 11

Peinaleopolynoe sp. nov. 1 Goffredi et al., 2017.

Type locality.

Hydrothermal vents of the Pescadero Basin in the Gulf of California, Mexico (23°57.23'N, 108°51.73'W), ROV "Doc Ricketts" Dive 757, 3700 m depth, 24 April 2015.

Material examined.

Type specimen: Holotype (SIO-BIC A6151) from the Pescadero Basin in the Gulf of California, Mexico (23°57.23'N, 108°51.73'W), ROV "Doc Ricketts" Dive 757, 3700 m depth, 24 April 2015; fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol. Paratypes: Two specimens (SIO-BIC A8597 and SIO-BIC A6166) from the same location as holotype; both fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol. Five specimens (SIO-BIC A6150, SIO-BIC A6155, SIO-BIC A6163, UNAM-ICML-EMU-12666) from the Pescadero Basin in the Gulf of California, Mexico (24°0'N, 108°49.98'W), ROV "Doc Ricketts" Dive 750, 3676 m depth, 18 April 2015; all five specimens fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol. One specimen (SIO-BIC A6312) from the Pescadero Basin in the Gulf of California, Mexico (24°0.00'N, 108°49.98'W), ROV "Doc Ricketts" Dive 751, 3676 m depth, 19 April 2015; fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol. One specimen (SIO-BIC A9989) from the Pescadero Basin in the Gulf of California, Mexico (23°57.37'N, 108°51.71'W), ROV “SuBastian” Dive S0196, 3688 m depth, 17 November 2018; fixed and preserved in 95% ethanol. One specimen (SIO-BIC A9988) from the Pescadero Basin in the Gulf of California, Mexico (23°57.41'N, 108°51.82'W), ROV “SuBastian” Dive S0196, 3670 m depth, 17 November 2018; fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol. Four specimens (SIO-BIC A10922, SIO-BIC A10921, SIO-BIC A10923, SIO-BIC A10003) from the Pescadero Basin in the Gulf of California, Mexico (23°56.51'N, 108°51.34'W), ROV “SuBastian” Dive S0197, 3692 m depth, 18 November 2018; all four specimens fixed in 95% ethanol and preserved in 50% ethanol. Two specimens (SIO-BIC A10001, SIO-BIC A9996) from the Pescadero Basin in the Gulf of California, Mexico (23°56.49'N, 108°51.35'W), ROV “SuBastian” Dive S0197, 3666-3667 m depth, 18 November 2018; one fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol, and one fixed in 95% ethanol and preserved in 50% ethanol. Eight specimens (SIO-BIC A10021, SIO-BIC A10025, SIO-BIC A10037, SIO-BIC A10020, SIO-BIC A10026, SIO-BIC A10022, SIO-BIC A10023, SIO-BIC A10024, SIO-BIC A10036) from the Pescadero Basin in the Gulf of California, Mexico (23°57.37'N, 108°51.71'W), ROV “SuBastian” Dive S0200, 3687-3688 m depth, 21 November 2018; three fixed in formalin and preserved in 50% ethanol, with elytra fixed and preserved in 95% ethanol, one fixed in 95% ethanol and preserved in 50% ethanol, and four fixed and preserved in 95% ethanol. One specimen (SIO-BIC A10926) from a vesicomyid clam bed near a whalefall in the Monterey Canyon, California (36°46.33'N, 122°4.99'W), ROV "Doc Ricketts" Dive 208, ~2900 m depth, 28 October 2010; fixed and preserved in 95% ethanol.

Description.

In life, large, overlapping, iridescent blue elytra covering the dorsum. Dorsum with ciliated transverse bands extending onto bases of elytrophores and dorsal tubercles. Chaetae extending beyond the width of elytra (Figs 6A-E View Figure 6 , 7A View Figure 7 , 8A View Figure 8 ). Twenty-one segments total (Fig. 8A, B View Figure 8 ). Elytra and elytrophores large, bulbous, nine pairs, on segments 2, 4, 5, 7, 9, 11, 13, 15, 17 (Fig. 8A View Figure 8 ). Elytra sub-reniform, thick, and greatly textured with large, bulbous macrotubercles along posterior margin (Figs 7A View Figure 7 , 8D View Figure 8 , 10B, E View Figure 10 ). Elytra on segment 17 curve to a lateral point in live specimen (Fig. 7A View Figure 7 ). Pharynx with seven dorsal border papillae and six ventral border papillae (Fig. 8C View Figure 8 ). Bilobed prostomium with triangular anterior lobes bearing short, thin, very delicate lateral antennae (= minute frontal filaments, sensu Pettibone 1993). Smooth median antenna with bulbous ceratophore in anterior notch. Eyes lacking. Pair of thick, smooth, tapering palps, ca. three times the length of prostomium (Fig. 8E View Figure 8 ). Segment 1 with dorsal and ventral pairs of smooth, tapering anterior cirri (= tentacular cirri, sensu Pettibone 1993), ca. the same length as palps. Ventral anterior cirri slightly shorter than dorsal anterior cirri. Cirrophores of anterior cirri long and cylindrical, each with small acicular lobe on inner side (Fig. 8E, F View Figure 8 ). Smooth ventral cirri on segments 2-21 (Figs 8B View Figure 8 , 9A, B View Figure 9 ). Buccal cirri of segment 2 modified, with bulbous ceratophores and longer styles, ca. four times the length of remaining ventral cirri (Fig. 8F View Figure 8 ). Buccal cirri attached to base of neuropodia. Ventral cirri on segments 3-21 attached to middle of neuropodia, with bulbous ceratophores and short, tapering styles. Dorsal cirri present on non-elytrigerous segments 3, 6, 8, 10, 12, 14, 16, 18, 20, 21 (Fig. 8A View Figure 8 ). Cirrophores of dorsal cirri cylindrical, rather long, fused to posterior sides of notopodia. Styles of dorsal cirri long, extending far beyond length of chaetae, filiform, tapering to fine tips. Segment 19 modified, lacking dorsal cirri and elytrophores (Fig. 8I View Figure 8 ). Arborescent branchiae compact, with numerous long terminal filaments, beginning on segment 3 (Fig. 8E View Figure 8 ) and continuing to segment 18 (Fig. 8I View Figure 8 ). Branchiae forming single large groups on elytrigerous segments, attached on bases of notopodia. Branchiae forming two groups on cirrigerous segments; small groups attached to dorsal tubercles and large groups attached near bases of notopodia (Fig. 8G View Figure 8 ). Nine pairs of thin rounded folds of unknown function attached to anterior sides of neuropodia on segments 4-12. On the right side, three additional thin rounded folds are visible on segments 13-15. Four pairs of ventral segmental papillae on segments 12-15 (Fig. 8B View Figure 8 ); small, rounded, and slightly cylindrical (Fig. 8H View Figure 8 ). Pygidium with a pair of anal cirri, not extending beyond the outline of the body (Fig. 8J View Figure 8 ). Parapodia biramous. Neuropodia ca. twice the length of notopodia, with an acicular process. On cirrigerous segments, notopodia with dorsal tubercles possessing small bundles of branchiae (Fig. 9A, B View Figure 9 ). Notopodia extending distally into acicular processes. Notochaetae in radiating bundles, stout, with double rows of spines (Fig. 9C View Figure 9 ); almost as long as neurochaetae. Neurochaetae slender, forming fan-shaped bundles (Fig. 9A, B View Figure 9 ). Superior neurochaetae (supra-acicular) with double rows of spines, and slightly curved tips (Fig. 9D View Figure 9 ). Inferior neurochaetae (sub-acicular) with double rows of teeth from the mid swelling to the hooked tips; smooth beneath the mid swelling (Fig. 9E View Figure 9 ). Inferior neurochaetae teeth are less prominent than the superior neurochaetae spines. Hooked jaws with small teeth on inner borders (Fig. 10A View Figure 10 ).

Morphological variation.

The holotype is 48 mm long, 27 mm wide, including chaetae. Smallest paratype (SIO-BIC A6312) is 21 mm long, 9 mm wide, including chaetae. Remaining paratypes range from 31-45 mm long, 18-26 mm wide, including chaetae. Paratypes vary in elytral color. Of the specimens examined, 19 individuals were collected with elytra remaining on the dorsum; the remaining specimens lost their elytra during the sampling process. SIO-BIC A8597, SIO-BIC A6155, SIO-BIC A10921, SIO-BIC A9996, SIO-BIC A10003, SIO-BIC A10923, SIO-BIC A10922, SIO-BIC A10021, and SIO-BIC A10020 (Fig. 11A View Figure 11 ) had the same iridescent blue elytra as the holotype. UNAM-ICML-EMU-12666, SIO-BIC A6150, SIO-BIC A10022, and SIO-BIC A10024 (Fig. 11B View Figure 11 ) had iridescent pink elytra; SIO-BIC A6312 (Fig. 11C View Figure 11 ), SIO-BIC A10025, and SIO-BIC A10001 had iridescent white elytra; SIO-BIC A6166 had iridescent black elytra (Fig. 11D View Figure 11 ); and SIO-BIC A10023 had red elytra (Fig. 11E View Figure 11 ). Some paratypes possess two pairs of ventral lamellae on segments 16-17 following the four pairs of ventral papillae on segments 12-15. Rounded ventral lamellae have similar orientation as papillae but flattened and not protruding as much toward posterior end. This dimorphism may be sexual, but it is presently unclear which sex is which.

Remarks.

Peinaleopolynoe orphanae sp. nov. is unique from the remaining Peinaleopolynoe taxa in that branchiae end on segment 18 (Table 5 View Table 5 ). Additionally, P. orphanae sp. nov. differs from its closest relative P. goffrediae sp. nov. in having small, rounded ventral papillae, as opposed to relatively long, laterally curved ventral papillae. The branchiae distributions range from segments 3-18 in P. orphanae sp. nov. but are present on segments 2-17 in P. goffrediae sp. nov.

Etymology.

Peinaleopolynoe orphanae sp. nov. is named after Dr. Victoria J. Orphan, not only for her invaluable research on deep-sea microorganisms, but also for her exploration of deep-sea chemosynthetic ecosystems and her love of the animals that thrive there.

Ecology.

Peinaleopolynoe orphanae sp. nov. is unusual among Peinaleopolynoe in that most specimens were associated with bacterial mats adjacent to hydrothermal vents in the Pescadero Basin at ~3700 m depth. One specimen (SIO-BIC A10926) was found at a cold seep with abundant vesicomyid clams suggesting that P. orphanae sp. nov. may be more of a habitat generalist than its close relatives.

Peinaleopolynoe orphanae sp. nov. displayed an interesting fighting behavior in situ (Fig. 6C, E View Figure 6 ), in which an individual used its everted pharynx to attack an opponent’s elytra; the two individuals attacked one another back and forth for several minutes (Suppl. material 2: movie). This may explain the damaged elytra with apparent bite marks on the posterior edges in the holotype (Fig. 7A View Figure 7 ) and in several other paratypes collected (Fig. 11A, B, E View Figure 11 ).