Serpula and Spiraserpula (Polychaeta, Serpulidae) from the Tropical Western Atlantic and Gulf of Guinea Author Bastida-Zavala, Rolando text ZooKeys 2012 198 1 23 http://dx.doi.org/10.3897/zookeys.198.3030 journal article http://dx.doi.org/10.3897/zookeys.198.3030 1313-2970-198-1 Serpula madrigalae sp. n. Figs 1 A-D2A-G 56 Type locality. Turks and Caicos. East of Caicos Island. Type material. Turks and Caicos. Holotype (USNM 1157006), RV Pillsbury, cruise 7106, sta. 1423, 21°41'N , 71°23'W , 10-feet otter trawl, 18 m, July 19, 1971 (ex UMML 22.1054). Description. Tube color greenish yellow (Fig. 2 A-B ); with five longitudinal ridges, lateral-most ridges larger than middle ones (Figs 1 C-D , 2 A-B ); lacking transverse ridges and peristomes; with four rows of alveoli, more evident between dorsal-most longitudinal ridges (Figs 1C, 2 A-B ). Body yellowish-brown, branchial crown and operculum yellow pale (preserved material only, Fig. 2C). TL= 20 mm; THW= 1.6 mm. Branchial crown with 18 radioles in each lobe; lacking branchial membrane. Peduncle smooth, with well-defined constriction (Fig. 2D); inserted in left lobe. Club-shaped pseudoperculum present. Operculum with moderately long, shallow, symmetrical funnel; lacking bulbous basal part (Figs 1A, 2 D-E ). OL= 2.3 mm, OD= 1.4 mm. Interradial grooves 1/3 of funnel length (Figs 1A, 2E). Funnel has 17 radii with rounded tips. Opercular inner surface with irregular tubercles (Figs 1B, 2D). Collar thick, with short ventral and dorsal lobes. Thorax consists of seven chaetigers. Collar chaetal fascicles symmetrical with regard to size and composition, unlike in some specimens of Serpula vossae sp. n. Bayonet chaetae with two blunt-elongate teeth, distal blade smooth, lacking proximal rasp (Figs 2F); hooded (capillary) chaetae present (Fig. 2G). Thoracic membranes well developed, narrowing toward to last thoracic chaetigers, fused ventrally, forming a short apron. Remaining six thoracic chaetigers with hooded (limbate) chaetae of two sizes; saw-shaped uncini. Anterior part of abdomen lacking distinct achaetous region. Anterior and middle abdominal chaetigers with flat-trumpet chaetae. Posterior chaetigers with 'capillary' chaetae. Anterior and posterior uncini saw-shaped. Figure 1. A-D Serpula madrigalae sp. n., from Turks and Caicos Islands, USNM 1157006, holotype A-B operculum in lateral and aboral views C-D tube in dorsal and frontal views E-F Serpula cf. vermicularis, from Nigeria, UMML 22.545 E-F operculum in lateral and aboral views. Figure 2. A-G Serpula madrigalae sp. n., from Turks and Caicos, USNM 1157006, holotype A-B tube and detail C entire body D-E operculum, in aboral and lateral views F bayonet chaetae G hooded (capillary) chaetae H-J Serpula cf. vermicularis, from Nigeria, UMML 22.545 H-I two distinct opercula in lateral and aboral views J bayonet chaetae. Etymology. Named after my wife, Dr Socorro Garcia-Madrigal , a specialist on crustaceans, who gave me the necessary encouragement and time to undertake this research. Distribution. Only recorded from the vicinity of Caicos Island, Turks and Caicos Islands (Fig. 6). Ecology. Sublittoral, 18 m. In the same sample there were other serpulids: Pomatostegus stellatus , Pseudovermilia multispinosa , Spirobranchus giganteus , and Vermiliopsis annulituba . Remarks. Serpula madrigalae sp. n. resembles other Serpula species with symmetrical,moderately long and shallow funnels, such as Serpula cavernicola , Serpula granulosa Marenzeller, 1884, Serpula israelitica Amoureux, 1976, Serpula jukesii Baird, 1865, Serpula narconensis Baird, 1865, Serpula oshimae Imajima & ten Hove, 1984, Serpula tetratropia Imajima & ten Hove, 1984 , Serpula vermicularis Linnaeus, 1767, and Serpula zelandica Baird, 1865. However, Serpula madrigalae sp. n. differs from all other Serpula species with regard to its characteristic tube which has five longitudinal ridges and four rows of alveoli (Figs 1 C-D , 2 A-B ). Serpula madrigalae sp. n. resembles Serpula vermicularis granulosa , in having tubercles on the internal surface of the operculum; however, the diagnosis of the latter species was brief ( Day 1973 ). At least Serpula madrigalae sp. n. differs by the tube with five longitudinal ridges and four rows of alveoli (Figs 1 C-D , 2 A-B ), while Serpula vermicularis granulosa is "faintly ridged" ( Day 1973 :131); also, Day (1973) mentioned more opercular radii (20-40) than present in Serpula madrigalae sp. n. (17, Figs 1B, 5). Serpula madrigalae sp. n. also resembles Serpula sp. A, from the northeastern part of the Gulf of Mexico, with regard to the shape of the operculum, the number of radii and the depths from which they were collected. However, they differ with regards to other features: Serpula madrigalae sp. n. has irregular tubercles on the internal surface of the operculum (Figs 1B, 2D) and lacks a proximal rasp in the bayonet chaetae (Fig. 2F), while Serpula sp. A lacks tubercles ( ten Hove and Wolf 1984 , Fig. 55-8a) and has bayonet chaetae with a proximal rasp. Additionally, ten Hove and Wolf (1984) mentioned that all the specimens lacked their tubes. Hence is not possible to assign the specimens recorded as Serpula sp. A. to Serpula madrigalae sp. n.