Rediscovery of Talehsapia annandalei (Polychaeta: Pilargidae) in Songkhla Lagoon, Thailand1

Sergio 1. Salazar-Vallejo,2 Eijiroh Nishi,3 and Saowapa Anguspanich 4

Abstract: The pilargid polychaete Talehsapia annandalei Fauvel, 1932, has been rediscovered in its type locality and its taxonomic affinities are clarified. The genus is set off from remaining synelmins based on possession of palps com­ pletely fused and absence of tentacular cirri. The "jawlike" structure is rather a symmetrical, discontinuous pair of denticulated bands and is not a true jaw.

FAUVEL (1932) DESCRIBED the polychaete little-known genus closely allied to Loandalia Talehsapia annandalei based on two specimens Monro. In her remarks, she commented that collected in Taleh-Sap, Thailand (Taleh-Sap Talehsapia differs from Loandalia in the lack of means the Songkhla inner sea or lagoon). palps and the presence of jaws. This affinity The taxonomic affinity of this taxon was with Loandalia had already been stated by enigmatic because of the presence of atypical Fauvel (in Mesnil and Fauvel 1939:39-40) "jaws" and the species was originally re­ after he rejected its original apparent affinity garded as incertae sedis; it did not seem to with euniceans and placed the genus in the belong to any of the then known polychaete Hesionidae. faInilies and it was regarded, questionably, as In her revision of the Pilargidae, Pettibone a very aberrant eunicid. In a later monograph (1966) questionably regarded Talehsapia as a Fauvel (1953) retained it as incertae sedis but junior synonym of Loandalia. Fauchald closely allied to Hesionidae and more specif­ (1977:78-79) kept the taxon as incertae sedis ically related to what we now call pilargids. because of its atypical jaws and even rejected, However, Fauvel did not accept the Pilargi­ following Emerson and Fauchald (1971), its dae as an independent family. Hartman recognition as a pilargid. This problematic (1947), in contrast, did regard Pilargidae as an genus was included in the Pilargidae but re­ independent family and included Talehsapia garded as being different from other pilargids Fauvel in her revision, but for her it was a by Salazar-Vallejo (1987, Salazar-Vallejo and So11s-Weiss 1992) on the basis oflack ofpalps and presence of jaws. Licher and Westheide 1 This work was partly supported by the Biodiversity (1994:225-226) thought that this genus is a Research and Training Programme in Thailand (BRT), the National Center for Genetic Engineering and Bio­ member of the Pilargidae. technology (BIOTEC), and the Thailand Research Fund The original description was published (TRF) grant 142016. Manuscript accepted 25 October 70 yr ago, and until now, no new specimens 2000. have been available to clarify this situation. 2 Departamento de Ecologia Acmitica, El Colegio de The second record of Talehsapia (Fauvel la Frontera Sur (ECOSUR), Apartado Postal 424, Che­ tumal, Q. Roo 77000, Mexico (E-mail: salazar@ecosur­ 1935) should be ascribed to Loandalia, as qroo.mx). Fauvel himself indicated (in Mesnil and Fau­ 3 Coastal Museum of Natural History, Yoshio, Kat­ vel 1939:39-40). The original specimens may suura, Chiba, Japan. Current address: Manazuru Marine be lost; in fact, several letters are still without Laboratory for Science Education, Yokohama National University, Iwa, Manazuru, Kanagawa 259-0202, Japan reply from Indian colleagues, and the loss of (E-mail: [email protected]). these specimens has yet to be confirmed. We 4 Prince of Songkla University, Hat Yai, Thailand examined the single slide deposited in the (E-mail: [email protected]). collections of the Universite Catholique de l'Ouest, Angers, and herein we present an analysis of the enigmatic features of this spe­ Pacific Science (2001), vol. 55, no. 3:267-273 © 2001 by University of Hawai'i Press cies on the basis of six additional specimens All rights reserved collected by one ofus (SA). The pharynx has

267 268 PACIFIC SCIENCE· July 2001 one pair of anterolateral glandular areas; in­ fusion of palps can be detected due to a slight ternally, at the same level, there is a unique depression on the anterior border of the reinforcement structure that might explain prostomium or by the longitudinal shallow the jawlike resemblance noted by Fauvel in furrow over the ventral side (Figure 1d). The the original description. The dorsal spine peristomium is without tentacular cirri. The starts on setiger 8, ventral cirri start on setiger anterior swollen portion includes setigers 1­ 4, and the pharynx can be 5-7 setigers in 5. Most specimens have cerebral eyes (Figure length. In most other features, the original Ie). The first parapodium is uniramous. Dor­ description byFauvel (1932) is fairly complete. sal spines start on setiger 8 and a ventral cir­ rus is present from setiger 4. Notosetae consist of the emergent dorsal spine and a MATERIALS AND METHODS thin, smooth, short capillary; neurosetae con­ All six specimens were collected by SA. on 8 sist of, up to nine per bundle, finely spinulose August 1998 in the Songkhla Lake (lagoon) capillaries arranged as about half supra­ (7°29' 17" N, 100° 24' 34" E). Sediments were ciculars and halfsubaciculars (Figure Ie). The sampled using a Tamura's grab (Rigosha Co., anal plate is a slightly swollen pigmented bulb 2 Japan, 0.05 m ) at O.5-m water depth and with three anal cirri; the two laterals are were mainly silty-clay or silty-clay loam. slightly longer than the smaller midventral Water salinity was 24 psu (range 0-24 psu), one. The anus is dorsal. water temperature was 33°C, dissolved oxy­ The eversible pharynx is in two rings but gen was 7.7 mglliter, and pH was 7.1. The in none of the specimens was it completely anterior region of two specimens was dis­ everted. The length of the everted portion is sected to remove the pharynx; one pharynx equivalent to the first four setigers. The was cross-sectioned close to the anterior end muscular region extends over 5-7 setigers. and the other was cut longitudinally. Refer­ The posterior muscular portion of the phar­ ence materials are deposited in the following ynx is an expanding cylinder, wider ante­ collections: Museum National d'Histoire riorly; the proximal ring is thin with two Naturelle, Paris; The Natural History Mu­ lateral glandular areas that can be stained seum, London; collections of the Prince of with rose-bengal; the distal ring is thick, Songkla University, Hat Yai, Thailand; heavily muscular, similar to a proventricle Coastal Museum of Natural History, Yoshio, (Figure 2a). Internally, at the same level, Katsuura, Chiba, Japan; and EI Colegio de la there is a complex set of symmetrical, dis­ Frontera Sur, Chetumal. The slide lEA N­ continuous denticulated bands at its anterior 44', corresponding with the type specimens, end (Figure 2b). In cross section, these bands deposited in the collection of the Universite are arranged as two curved, fusiform, oblique Catholique de l'Ouest, Angers, was examined. structures that become thinner toward their lateral joint (Figure 2e). There are a few truncated papillae pointing toward the inside RESULTS of the pharynx (Figure 2d); the denticulated Two specimens were incomplete posteriorly. bands are rugose due to many tiny denticles One of the complete ones was dissected to (Figure 2e). These areas project posteriorly examine the pharynx, and an anterior frag­ and can be seen from the outside of the body ment was also dissected. Specimens average as two short, thin, darker lateral lines; if seen 98 setigers (range 55-157) and 27 mm in in cross section, they are slightly thicker or length (15-52 mm). The body has the gen­ provided with more pigment. eral Loandalia-like appearance; the anterior A ventral dissection ofthe pharynx (Figure end is swollen and there frequently are pig­ 3a) shows that there are two rows of alter­ mented glands along the sides of the body nating marginal papillae, with eight rounded (Figure 1a). The prostomium is rounded, an­ papillae on the outer ring (Figure 3b), and teriorly smooth, with completely fused palps one or two inner, distally truncated papillae and without antennae (Figures la-c). The (Figure 3e). The darker portions correspond Rediscovery of Talehsapia annandalei in Thailand . Salazar-Vallejo et al. 269

FIGURE 1. Talehsapia annandalei Fauvel. a, Anterior end of a complete specimen with the pharynx everted; note the lateral glands on the pharynx and pigmented lateral glands on the body; b-c, anterior end of other specimens showing its completely fused palps; d, cross section ofa specimen showing the midventral depression on the prostomium (scales: a, 1 mID; b, 0.5 mID; c, 0.3 mID; d, 0.1 mID). to two groups of lateral, symmetrical, discon­ longer than the dorsal one. They have poly­ tinuous denticulated bands that taper at both hedric denticles, and over the darker adjacent ends; each seems to be provided with a pos­ areas there are other slightly wider polyhedric terior projection (Figure 3c). Upon closer in­ denticles. Some of the denticles are located spection (Figure 3d), the lateral bands are over the inner margin of the band (directed slightly different because the ventral one is posteriorly) and appear longer than the rest. 270 PACIFIC SCIENCE· July 2001

FIGURE 2. Talehsapia annandalei Fauvel. a, Dorsal view of the pharynx (dissected), widest at the anterior end; b, anterior end enlarged, note the laterally duplicated structures; c, cross section of the pharynx (ventral side is up), note the lateral discontinuity of the structures; d, close-up of an inner papilla showing truncated tip; e, close-up of the dorsal denticu­ lated band showing tiny denticles (scales: a, 450 11m; b, 270 11m; c, 360 11m; d, e, 120 11m).

The slide IEA N-44' is labeled as "Taleh­ to the original illustrations by Fauvel and the sapia annandalei Fauvel n. gen., n. sp., Taleh­ ventral cirri, where present, can still be seen. Sap, St. 27." It contains three parapodia but it These specimens are consistent with the is partly dried and because of the adsorbed original description of Talehsapia annandalei salt over the setae, their fine spinulation can­ Fauvel and because they come from the type not be observed. These parapodia are similar locality, we consider them to belong to the Rediscovery of Talehsapia annandalei in Thailand . Salazar-Vallejo et al. 271

FIGURE 3. Takhsapia annandalei Fauvel. a, Everted pharynx from Figure la, dissected ventrally; b, close-up of the outer midventral rounded papillae; c, sketch from Figure 3a to illustrate the relative position and size of the denticulated bands; d, denticulated bands with granular appearance; the one on the right is ventral, note lateral discontinuity (scales: a, 110 1lIIl; b, 48 11m; c, 140 11m; d, 48 1lIIl).

same species. This pilargid is known only tonereis (Nereididae), and Nephtys (Neph­ from the type locality: Taleh-Sap, Gulf of tyidae). Thailand (formerly Gulf of Siam). Taleh-Sap means the inner sea of Songkhla (or Singora DISCUSSION [7.12° N, 100.36° ED. Taleh-Sap is a large estuary on the eastern side of the Malacca When working with the original material, Peninsula, opening to the Gulf of Thailand. Fauvel (1932) placed one specimen in lactic Associated polychaete species are Namalycas­ acid and compressed it, and he noticed a re­ tis indica Southern (Nereididae), Sigambra sistant paired structure that gave the impres­ pukhetensis Licher & Westheide (Pilargidae), sion of a horizontal jaw complex resembling and at least one species each in Prionospio the algebraic symbols <), which he regarded (Spionidae), Heteromastus (Capitellidae), Cera- as a two-piece jaw. Without compression, 272 PACIFIC SCIENCE· July 2001 however, these reinforcements are arranged support by Consejo Nacional de Ciencia y as two fusiform, oblique structures that are Tecnologia (CONACYT), Mexico (32529­ laterally discontinuous, which explains the T) and thanks H. Poupon from the Institut original observation. The pharyngeal struc­ de Recherche pour Ie Developpement, ture of Talehsapia annandalei has a slight re­ France; A. Crosnier and F. Pleijel from the semblance to the trepan of syllid polychaetes Museum National d'Histoire Naturelle, (Autolytinae or Eusyllinae). Although it re­ Paris; and P. Gillet from the Universite sembles those found in Autolytus magnus Catholique de l'Ouest, Angers. H. Bahena Berkeley (Imajima 1966a:41, fig. ge), Eusyllis from El Colegio de la Frontera Sur, Mexico, longicirrata Imajima (1966b:95, fig. 30b), and made the photographs. The critical reading E. inflata Marenzeller (Imajima 1966b: 100, by two anonymous referees and by S. Monks fig. 32b), the denticulated bands of Talehsapia improved the language. are different with regard to several features. In Talehsapia they are discontinuous and al­ Literature Cited most symmetrical, and the teeth are abundant and less differentiated than in the syllids. Emerson, R. R., and K. Fauchald. 1971. A Also, they are apparently not restricted to the revision of the genus Loandalia Monro lateral bands of the pharynx. This may be re­ with description of a new genus and spe­ garded, however, as a convergent feature. cies of pilargiid polychaete. Bull. South. The pharynx of pilargin pilargids has been Calif. Acad. Sci. 70:18-22. described as being provided with small den­ Fauchald, K. 1977. The polychaete worms: tides; Pettibone (1966: 179, fig. lIe) noticed Definitions and keys to the orders, families that Cabira Webster has oblique rows ofsmall and genera. Nat. Hist. Mus. Los Angel. dentides, and Katzmann et al. (1974: 10-11, Cty. Sci. Ser. 28:1-188. figs. 4A,B) found that Aneistrosyllis McIntosh Fauvel, P. 1932. Annelida Polychaeta of the has an irregularly denticulated band with Indian Museum, Calcutta. Mem. Indian denticles of two sizes, the dorsal being larger Mus. 12:1-262. than the ventral ones. The symmetrical, dis­ 1935. Annelides polychetes de continuous denticulated bands in Talehsapia l'Annam. Mem. Pont. Acad. Sci. Novi seem to be unique within the family. Lyncaei, ser. 3, 2:279-354. Talehsapia is a pilargid and thus should be --. 1953. The fauna of India, including assigned to the subfamily Synelminae Salazar­ Pakistan, Ceylon, Burma and Malaya. An­ Vallejo. Its independent generic status can be nelida Polychaeta. Indian Press, Allahabad. recognized because of its diagnostic features: 507 pp. completely fused palps, lack of antennae or Hartman, O. 1947. Polychaetous annelids, 8. tentacular cirri, and presence of symmetrical, Pilargiidae. Allan Hancock Pac. Exped. discontinuous denticulated bands in the mus­ 10:483-523. cular portion of the pharynx. These struc­ Imajima, M. 1966a. The Syllidae (poly­ tures are not true jaws because they lack chaetous annelids) from Japan, 2. Autoly­ prominent solid structures, cusps, or any of tinae. Publ. Seto Mar. BioI. Lab. 14:27­ the other salient features typically associated 83. with jaws; thus pilargids can be regarded as --. 1966b. The Syllidae (polychaetous jawless polychaetes. annelids) from Japan, 3. Eusyllinae. Publ. Seto Mar. BioI. Lab. 14:85-116. Katzmann, W., L. Laubier, and ]. Ramos. ACKNOWLEDGMENTS 1974. Pilargidae (Annelides Polychetes er­ SA thanks A. Siripech, M. Charoenpomthip, rantes) de Mediterranee. Bull. Inst. Oce­ K. Ruangnu, and]. Jailuk. E.N. thanks the anogr. (Monaco) 71:1-40. staff of the Coastal Museum of Natural His­ Licher, F., and W. Westheide. 1994. The tory, Katsuura, Japan, for their support dur­ phylogenetic position of the Pilargidae ing the work. S.I.S.-V. acknowledges the with a dadistic analysis of the taxon-facts Rediscovery of Talehsapia annandalei in Thailand . Salazar-Vallejo et al. 273

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