Rev. Biol. Trop. 49. Supl. 2: 37-67, 2001 www.rbt.ac.cr, www.ucr.ac Some Nereididae (Annelida: Polychaeta) from the Pacific Coast of Costa Rica Harlan K. Dean Department of Invertebrate Zoology, Museum of Comparative Zoology, 26 Oxford St., Cambridge, MA 02138 USA. FAX: 617-495-5667. E-mail: [email protected] (Received 28-VI-2000. Corrected 23-II-2001. Accepted 6-IV-2001) Abstract: Fifteen species of Nereididae (Annelida: Polychaeta) belonging to nine genera are reported from the subtidal and intertidal of the Pacific Coast of Costa Rica. A new species, Nereis costaricaensis, is described. Laeonereis brunnea Hartmann-Schröder 1959 is removed from synonomy with L. culveri (Webster 1880) while Perinereis seridentata (Hartmann-Schröder 1959) is moved from the genus Neanthes based upon the presence of bar- shaped paragnaths on area VI of the proboscis. The presence of Neanthes micromma Harper 1979 is an extension of the range of this species from the Gulf of California and Neanthes roosevelti Hartman 1939 is the first record of this species since its description from the Galapagos. A taxonomic key to these nereidid species is included. Key words: Polychaeta, Nereididae, Costa Rica, Tropical, Eastern Pacific. Members of the family Nereididae are a studied (Hartman 1940; Fauvel 1943; de León- common component of most marine (and González & Solís-Weiss 1998, 2000), those of some freshwater) communities ranging from the Panamic Province are less well known. the intertidal to abyssal depths. This family Monro (1928, 1933) listed twelve species of con-tains a large number of genera and Nereididae from the Pacific side of Panama species; Hilbig (1997), for example, and the Galapagos Islands while Fauchald recognized 37 genera and about 400 described (1977) reported nine species mainly from species. The nereidids are considered to be rocky shores of Pacific Panama. Studies of the discretely mo-bile, producing mucous tubes to Jaltepeque estuary in El Salvador by Hartmann- form a tempo-rary living space. They are often Schröder (1959) and Molina-Lara & Vargas- viewed as carnivores due to their formidable Zamora (1995) recorded four species of jaws; how-ever, they have also been reported to nereidids. Dean (1996 a, b) listed ten species be deposit feeders, feeding on such things as of nereidids from the Gulf of Nicoya and algae, bacte-ria and detritus (Fauchald & Golfo Dulce both on the Pacific side of Costa Jumars 1979). There is even evidence of filter Rica although many of these were identified feeding in at least one species of Nereis only to the genus level. This paper reexamines (Goerke 1966, Esselink & Zwarts 1989). many of these nereidids previously collected While the shallow water nereidids of the subtidally and listed by Dean (1996 a, b) as Mexican Province of the Tropical Eastern well as more recently collected material from Pacific Biogeographic Region have been well the intertidal and shallow subtidal of these two 38 REVISTA DE BIOLOGIA TROPICAL estuaries. A total of fifteen species belonging to nine genera are included here. MATERIALS AND METHODS Subtidal material was collected in the Gulf of Nicoya using a modified Smith-McIntyre bottom grab. Subtidal station sites and sediment characteristics may be found in Maurer & Var- gas (1984) and Vargas (1995). Intertidal speci- mens were collected in the Punta Morales area of the Gulf of Nicoya by the author during a Fig. 1 & 2. Nereis costaricaensis n. sp.: Fig. 1, extended series of collecting trips partially supported by proboscis, dorsal view; Fig. 2, extended proboscis, ventral the Universidad de Costa Rica’s Centro de In- view. vestigación en Ciencias del Mar y Limnología (CIMAR) or by H. Buttner from the Center for must be dissected by making a ventral incision Tropical Marine Ecology (ZMT), Bremen, Ger- to the side of the body midline, both through many, who also collected at Jicaral. Shallow the body wall as well as the invert-ed muscular subtidal samples taken at Punta Islotes and proboscis, in order to expose its inner surface. Sandalo in Golfo Dulce were collected by J. Other taxonomically valuable characters are Cortés and/or A. Fonseca. Voucher specimens presence or absence of eyes and the of most of these species, as well as the type occurrence and morphology of falcigers in the specimen and paratypes of Nereis notopodial and neuropodial setal bundles. The costaricaensis n. sp. have been deposited in the falcigers, especially those in the notopodia, may Museum of Comparative Zoology (MCZ), not be present in anterior or middle setigers so Harvard Uni-versity, Cambridge, MA USA inspection of setae in far posterior setigers is and the Museo de Zoología, Universidad de often necessary. Costa Rica. Morphology: The nereidids are easily recog- Key to some species of Nereididae collected nized due to their large biramous palps, formi- from the Pacific coast of Costa Rica dable jaws, and two to four pairs of tentacular cirri on the peristomium. With the exception 1. Proboscis lacking both papillae and parag- of the first two setigers, the parapodia are naths. Dorsal cirrus inserted subdistally on usually biramous with varying numbers of greatly expanded upper notopodial ligule in parapodial lobes in each ramus. Both the posterior setigers…………. Leptonereis laevis notopodia and neuropodia may be composed 1a. Proboscis with papillae and/or paragnaths. of an acicular lobe as well as an upper and ……………………………………………….2 ventral ligule and the relative size and shape of these ligules are of great taxonomic value. The 2. Proboscis with papillae, paragnaths absent. surface of the eversible proboscis may be ……………………………………………….3 subdivided into eight recognizable areas (Fig. 2a. Paragnaths present……………………….4 1 & 2) and the presence or absence of fleshy papillae or hard-ened paragnaths, as well as 3. Jaws lacking teeth, dorsal cirris long, slender the shape of these paragnaths, is also of in posterior setigers…Gymnonereis crosslandi taxonomic importance. The regions of the 3a. Jaws with teeth, notacicular lobe long, proboscis may be easily seen if the animal is conical, upper notopodial ligule absent in preserved with its probos-cis extruded, posterior setigers………..Laeonereis brunnea sometimes made possible just prior to fixation 4. Paragnaths present on maxillary ring of by the application of slight pressure just proboscis only, blades of falcigers posterior to the proboscis region forcing the unidentate... proboscis to evert. More usually the proboscis ……………………….Ceratonereis singularis ECOSISTEMAS ACUATICOS DE COSTA RICA II 39 4a. Paragnaths present on both maxillary and setigers, falciger blades short, curved, with oral ring of blunt distal proboscis………………………...5 tip…………………....Neanthes pseudonoodti 12a. Upper notopodial ligule not long and 5. Pectinate and/or transverse paragnaths narrow………………………………………1 present……………………………………….. 3 6 5a. Only conical paragnaths present…….…...8 13. Paragnaths absent on areas I, II, II and V; falciger blades long with blunt distal hook; 6. Transverse, pectinate, and conical parag- upper notopodial ligule foliose with sub- naths present, dorsal cirrus inserted terminally distally inserted dorsal cirrus in posterior on superior notopodial ligule in posterior setigers…………………..Neanthes micromma setigers…………. Pseudonereis gallapagensis 13a. Paragnaths present on all areas of the 6a. Either transverse or pectinate paragnaths proboscis present in addition to cones but not …………………...………………14 both…….7 14. Upper notopodial ligule greatly expanded 7. Pectinate paragnaths present in addition to with subdistally inserted dorsal cirrus in cones, notopodial homogomph falcigers with posterior setigers; areas VII and VIII with two strongly curved blade and small subdistal irregular rows of paragnaths……….…………. tooth. …………………...Platynereis dumerilii ………………………….…Neanthes succinea 7a. Pectinate paragnaths absent, 16-24 trans- 14a. Upper notopodial ligule reduced or absent verse paragnaths in a single row on area VI….. in posterior setigers, areas VII and VIII with a ….……………………..Perinereis seridentata broad band of cones……...Neanthes roosevelti 8. Notopodial homogomph falcigers present..9 Species Descriptions 8a. Notopodial setae all compound spinigers ……………………………………….…....12 Ceratonereis singularis Treadwell, 1929 Fig. 3-6 9. Area VII and VII of proboscis with paragnaths in two or three rows…………… Ceratonereis singularis Treadwell 1929: 1. -- 10 Perkins 1980: 17. --Salazar-Vallejo & Jimé- 9a. Area VII and VIII of proboscis with a few nez-Cueto 1997: 365. --De León-González (four in the single specimen examined) parag- and Solís-Weiss 2000: 550. naths in a single row……………. Nereis riisei Ceratonereis singularis austalus Hartmann- Schröder 1985: 46-47. 10. Area I with numerous (14-22) paragnaths Ceratonereis mirabilis: --Ehlers 1887: 117. -- ………………………….…Nereis oligohalina Treadwell 1939: 222. --Hartman 1956: 248; 10a. Area I with one to four paragnaths……11 1968: 505. --Rioja 1960: 249; 1962: 166. -- Fauchald 1973: 21. --Gardiner 1976: 147. 11. Area I of proboscis with three to four Ceratonereis crosslandi: --Dean 1996b: 83. paragnaths; notopodial falciger a finely toothed, Ceratonereis tentaculata : --Hartman 1940: 218. blunt-tipped rod………………...Nereis zonata --Rioja 1941: 705. 11a. Area I of proboscis with one to two Nereis (Ceratonereis) tentaculata: --Berkeley paragnaths; notopodial falciger with straight, & Berkeley 1960: 359. coarsely toothed blades………………………. ………………….. Nereis costaricaensis n. sp. Material Examined: Golfo Dulce, Punta Islo- tes, 8°43'41" N, 83°23'8"