Phragmatopoma balbinae, Chávez-López, 2020

Chávez-López, Yessica, 2020, New species and new records of Phragmatopoma (Polychaeta: Sabellariidae) from Tropical America, Zootaxa 4845 (3), pp. 301-330 : 317-319

publication ID	https://doi.org/ 10.11646/zootaxa.4845.3.1
publication LSID	lsid:zoobank.org:pub:D737FF5C-63F8-4E80-A605-789A5FEB1B2C
DOI	https://doi.org/10.5281/zenodo.4476974
persistent identifier	https://treatment.plazi.org/id/977F915B-FFAF-FFCB-FF7C-FB5BFA26FAC7
treatment provided by	Plazi
scientific name	Phragmatopoma balbinae
status	sp. nov.

Treatment

Phragmatopoma balbinae View in CoL n. sp.

Figures 8 View FIGURE 8 A–I, 12D–F

LSID: urn:lsid:zoobank.org:act:3D6F8225-7966-4CD3-B5E6-DDCF7B79B7C2

Type material. Holotype: ECOSUR0229 View Materials , La Condesa, Acapulco, 16°51’23”N, 99°52’08”W, Guerrero, Mexico, southern Mexican Pacific ; November 27, 1999, S.I. Salazar-Vallejo coll. GoogleMaps ); Paratypes: ECOSUR0230 View Materials , five spec. from La Condesa, Acapulco, same as holotype .

Additional material: One specimen. Guerrero: ECOSUR-P3097, ( Acapulco , 16°51’27”N, 99°52’17.1”W, on bivalve mollusk Striostrea prismatica (Gray, 1825) , 5–15 m, May 25, 2000, coll. A. Medina-López) GoogleMaps .

Description. Color pattern of preserved specimens. Body light brown ( Fig. 8A View FIGURE 8 ). Outer paleae with amber blade and dark amber handle; median plume translucent ( Fig. 8D View FIGURE 8 ). Middle paleae cherry with handle amber ( Fig. 8E View FIGURE 8 ). Inner paleae amber ( Fig. 8F View FIGURE 8 ). Opercular papillae dark brown ( Fig. 8C View FIGURE 8 ). Median ridge with brown eyespots ( Fig. 8C View FIGURE 8 ). Tentacles light brown ( Fig. 8 View FIGURE 8 B–C). Building organ and thorax light brown with brown spot in all surfaces ( Fig. 8 View FIGURE 8 B–C). Parathoracic chaetae translucent ( Fig. 8 View FIGURE 8 G–H). Third parathoracic segment with abundant brown spots, in ventral region. Abdominal neuropodia with a series of brown spots, abundant in distal segments. Abdominal neurochaetae and uncini translucent ( Fig. 8I View FIGURE 8 ). Caudal peduncle light brown with brown lateral spots ( Fig. 8A View FIGURE 8 ).

Body. Complete specimen of 9 mm total length; parathoracic region 0.7 mm wide; 25 abdominal segments; caudal peduncle 1 mm long ( Fig. 8A View FIGURE 8 ).

Operculum. Opercular crown and opercular stalk completely fused. Opercular crown conical and oval, protruding in lateral view ( Fig. 8 View FIGURE 8 A–C). Three rows of paleae, only two visible: 58 outer paleae, 23 middle and inner paleae. Outer paleae geniculate with a pair of heterodont teeth, one straight and the other slightly curved; flat blade 1/3 longer than wide, serrated margin, without transversal thecae visible; median plume short, almost 2/3 as long as blade, rounded, twice longer than wide, filamentous with thin filaments, 1/3 as long as plume ( Fig. 8D View FIGURE 8 ). Middle paleae strongly geniculate with elevated peak, rough surface without visible transversal thecae; sub-quadrangular nape, decurrent, serrated surface, wider than peak, almost 2/7 as long as peak; chin slightly longer than wide, margin serrated; sharp tip markedly falcate, with smooth margin ( Fig. 8E View FIGURE 8 ). Inner paleae strongly geniculate, serrated, elevated peak, five times longer than wide, and transversal thecae present; nape smooth; tip with filaments ( Fig. 8F View FIGURE 8 ). Papillae small and oval. Oral tentacle unbranched. Median ridge long, 2/3 as long as opercular stalk, with marginal eyespots ( Fig. 8C View FIGURE 8 ). Median organ absent. Building organ with ‘U’ shape.

Thorax. Chaetiger 1 with a pair of neuropodial capillary chaetae ( Fig. 8A View FIGURE 8 ). Chaetiger 2 with a pair of lateral cirrus, neuropodia with capillary chaetae and a pair of branchiae.

Parathorax. Three parathoracic segments. Chaetigers with a pair of branchiae. Notopodia with lanceolate chaetae interspersed with capillary of similar length ( Fig. 8H View FIGURE 8 ). Neuropodia with lanceolate chaetae; neurochaetae thinner than notochaetae.

Abdomen. Segments with a pair of branchiae decreasing in size towards posterior segments; absent in the last nine chaetigers. Neurochaetae verticillate of different length. Notopodia with a series of uncini with six pairs of teeth ( Fig. 8I View FIGURE 8 ).

Caudal region. Caudal peduncle elastic and smooth ( Fig. 8A View FIGURE 8 ).

Tube. Tubes with fine sand. Bryozoans and serpulids incrusted; syllids associated ( Fig. 12 View FIGURE 12 D–F).

Variation. The number of paleae varied from 45–60 in outer paleae, and 18–22 in middle paleae (n= 3 spec.).

Habitat. Phragmatopoma balbinae n. sp. has been found on the oyster S. prismatica , in the sublittoral zone (5–15 m).

Distribution. Only known from La Condesa, Acapulco, Guerrero, Mexico ( Fig. 13 View FIGURE 13 ).

Etymology. This new species is named after the author’s mother, Balbina López Gutiérrez.

Remarks. Of all described species of Phragmatopoma , P. balbinae n. sp. is similar to P. peruensis only in body size, according to Hartman (1944); to P. attenuata by its conic opercular crown; and to P. digitata by morphology of outer paleae. However, P. attenuata has outer paleae with filamentous median plume, with thin and long filaments, almost longer than the blade ( Fig. 2C View FIGURE 2 ), in contrast with P. balbinae n. sp. that has outer paleae with filamentous median plume, with thin and short filaments, 1/3 as long as blade ( Fig. 8D View FIGURE 8 ). Also, the middle paleae with straight nape and peak, and curved tip in P. attenuata ( Fig. 2J View FIGURE 2 ) is different from decurrent nape, elevated peak and very falcate tip of P. balbinae n. sp. ( Fig. 8E View FIGURE 8 ).

Phragmatopoma balbinae n. sp. and P. digitata are similar in its outer paleae, but the blade in P. balbinae n. sp. is 1/3 longer than wide, with a median plume long (2/3 as long as blade) ( Fig. 8D View FIGURE 8 ), while in P. digitata the blade is twice longer than wide and the length of its median plume is barely ½ of the total length of the blade ( Fig. 5 View FIGURE 5 E–F). Additionally, P. balbinae n. sp. specimens are small, only 9 mm long and the mean size of P. digitata is 10.8 mm.