Two new species of Ancistrosyllis McIntosh, 1878 (Annelida: Pilargidae) from the Gulf of Thailand, Western Pacific.

Two new species of Pilargidae, Ancistrosyllis eidimtaiteae sp. nov. and A. suksani sp. nov., are described from the Gulf of Thailand. These Ancistrosyllis are characterized by having a median and two lateral antennae. Ancistrosyllis eidimtaiteae sp. nov. differs from all other species in the group by having brown pigmentation and by having both short antennae and tentacular cirri, first notopodial hooks from chaetiger 3, and a single type of neurochaetae (long non-limbate capillaries with bifid tips). Ancistrosyllis suksani sp. nov. can be distinguished from other species of Ancistrosyllis by the presence of the first notopodial hooks from chaetiger 4 and three types of neurochaetae (short, stout, falcates with a subdistal small guard, short limbates, and long bifid non-limbates). An updated key to the Ancistrosyllis species of this group is also provided.

Four new species of Pilargidae (Annelida: Pilarginae) from the Gulf of Thailand.

Four new species belonging to the Family Pilargidae, Ancistrosyllis kornkanokae sp. nov., A. nakkaritae sp. nov., Cabira saithipae sp. nov., and C. thailandica sp. nov. were collected from 927 m depth in soft sediments in the Songkhla Sea, Gulf of Thailand. Ancistrosyllis kornkanokae sp. nov. can be distinguished from other species in the genus by the presence of a small median antenna on the prostomium; two pairs of elongate tentacular cirri; and short limbate neurochaetae with unidentate curved pointed tips. Ancistrosyllis nakkaritae sp. nov. is characterized by having a conspicuous median antenna and elongate lateral antennae longer than palps; and short limbate neurochaetae with bifid tips. While Cabira saithipae sp. nov. is characterized by the presence of the first notopodial hook at chaetiger eight, large, conical papillae ont chaetigers 717 and the presence of both short, recurved tipped and short, curved tip chaetae in anterior chaetigers. Cabira thailandica sp. nov. is distinguished from other species in the genus by the first notopodial hooks occurring at chaetiger seven and the presence of long, non-limbate capillary neurochaetae with bidentate tips. Updated keys to the genera Ancistrosyllis and Cabira are also provided.

New Species of Cirratulidae (Annelida, Polychaeta) from the Caribbean Sea.

Fifteen species in seven genera of Cirratulidae are reported from shallow-water collections in the Caribbean Sea primarily as part of the Caribbean I expedition of the research vessel Alpha Helix in 1977 and smaller separate collections from Panama and Venezuela. Thirteen species, all bitentaculates, are new to science. New species include Aphelochaeta caribbeanensis n. sp.; six species of Caulleriella: C. angusticrista n. sp., C. convexacapa n. sp., C. microbidentata n. sp., C. parapicula n. sp., C. parvinasa n. sp., and C. quadrata n. sp.; Chaetozone dossena n. sp.; three species of Kirkegaardia: K. filiformis n. sp., K. panamaensis n. sp., and K. playita n. sp.; and two species of Dodecaceria: D. alphahelixae n. sp. and D. dibranchiata n. sp. Additionally, two multitentaculate cirratulids, Cirriformia sp. from Panama and Timarete punctata (Grube, 1859) from Nicaragua are reported.

Some intertidal and shallow water polychaetes of the Caribbean coast of Costa Rica / Poliquetos de la zona intermareal y aguas someras de la costa del Caribe costarricense

Abstract:The polychaete fauna of the Caribbean coast of Costa Rica has been inadequately characterized with only nine species previously reported. Collections of polychaetes from intertidal coralline rocks and several shallow sub-tidal sites on the Caribbean coast of Costa Rica have been examined and 68 species were identified. Of these, 66 are new records for Costa Rica. Rev. Biol. Trop. 65 (1): 127-152. Epub 2017 March 01.

ResumenLa fauna de poliquetos en la costa del Caribe costarricense se ha descrito inadecuadamente con solo 9 especies reportadas anteriormente. Se estudiaron los poliquetos de de las rocas coralinas intermereales y varios sitios submareales someros en la costa del Caribe costarricense y se identificaron 68 especies, de las cuales 66 son nuevos registros para Costa Rica.

Some intertidal and shallow water polychaetes of the Caribbean coast of Costa Rica.

The polychaete fauna of the Caribbean coast of Costa Rica has been inadequately characterized with only nine species previously reported. Collections of polychaetes from intertidal coralline rocks and several shallow sub-tidal sites on the Caribbean coast of Costa Rica have been examined and 68 species were identified. Of these, 66 are new records for Costa Rica.

Aphelochaeta (Polychaeta: Cirratulidae) from the Pacific coast of Costa Rica, with a description of five new species.

Five new species of bitentaculate Cirratulidae belonging to the genus Aphelochaeta are herein described from the Pacific coast of Costa Rica, all from shallow subtidal depths. Aphelochaeta antelonga sp. nov. is characterized by a long biannulate peristomium and fibrillated capillary setae and is from 11-18 m in the Gulf of Nicoya. Aphelochaeta guimondi sp. nov., with a wide dorsal trough in the thorax and hirsute capillaries (visible using SEM), is described from 11-26 m in the Gulf of Nicoya. Aphelochaeta praeacuta sp. nov., with its first peristomial annulation extending as a dorsal crest over the second annulation and first setiger, was collected from 11-28 m in Bahia Culebra. Aphelochaeta striata sp. nov., collected from 11-28 m in the Gulf of Nicoya, is recognized by its narrow body and the transverse blue stripes across the venter of setigers 5-8 produced with methyl green stain. Aphelochaeta zebra sp. nov., collected from a coral reef in Golfo Dulce, is characterized by its expanded posterior end and the darkly staining intersegmental regions using methyl green stain. Additionally, A. glandaria Blake, 1996, a species reportedly with a widespread geographic distribution (Blake, 1996), was also encountered subtidally from the Gulf of Nicoya and Golfo Dulce.

The Orbiniidae (Annelida: Polychaeta) of Pacific Costa Rica.

Seven species of Orbiniidae are described from the Pacific coast of Costa Rica including two new species. Leodamas hamatus n. sp., a commonly occurring species on the coast of Pacific Costa Rica, is described from 11‒18 m in the Gulf of Nicoya and Bahia Culebra. This species is unusual in that the neuropodial uncini differ morphologically from anterior to posterior in the thorax. Scoloplos cryptospinigerus n. sp. is described from 18-22 m in the Gulf of Nicoya and has only a few short, toothed spines amidst numerous capillary setae in most of the thoracic neuropodia. This arrangement of thoracic neurosetae is unusual and has been seen only in one other described species of Scoloplos from Australia.

Depth diversity profile of polychaete worms in Bahía Chatham, Isla del Coco National Park, Costa Rican Pacific / Perfil de diversidad en profundidad de gusanos poliquetos en Bahía Chatham, Parque Nacional Isla del Coco, Pacífico costarricense

The subtidal benthos of tropical islands has been poorly studied in the Eastern Tropical Pacific. Several studies have been published on taxonomic collections from oceanic islands in the region, but ecological features and community structure are practically unknown. In the present study, composition of the polychaete community along a depth gradient from the sand bottom of Bahía Chatham, Isla del Coco National Park, Costa Rica is analyzed. Fifty species of polychaetes belonging to 28 families were found. There is a peak in diversity, abundance and richness at 28-30m. The lowest values occurred at 50m depth with values increasing below this depth. The composition of species changed with depth with some species being found only at depths either less than or greater than 50m. This pattern can be explained in part by the location of the thermocline that occurred at around 50m depth.

El bentos submareal de las islas tropicales ha sido poco estudiado en el Pacífico Oriental. Varios estudios se han publicado sobre colecciones taxonómicas de las islas oceánicas de la región, pero las características ecológicas y la estructura de la comunidad son prácticamente desconocidas. En el presente estudio se muestra la composición de la fauna de anélidos poliquetos según un gradiente de profundidad en los fondos arenosos de la Bahía de Chatham, Parque Nacional Isla del Coco, Costa Rica. Cincuenta especies de poliquetos repartidas en 28 familias fueron encontradas. La comunidad muestra un pico en la diversidad, abundancia y riqueza a los 28-30m. Los valores fueron menores a 50m mientras que por debajo de esta profundidad se observó una tendencia hacia un aumento en la riqueza de la comunidad. La composición de las especies cambió de acuerdo a la profundidad y algunas especies sólo se encontraron por debajo o por arriba de los 50m. La ubicación de la termoclina en la profundidad de 50m podría explicar en parte el patrón encontrado.

On Branchiostoma californiense (Cephalochordata) from the Gulf of Nicoya estuary, Costa Rica

The cephalochordates are represented by the lancelets, of which species of the genus Branchiostoma are the best known. In recent years, these organisms have been the center of activity of studies focusing on the phylogenetic relationships of the chordates. In 1980, a survey of the benthos at 48 stations in the Gulf of Nicoya estuary, Pacific coast of Costa Rica, yielded 265 specimens of the lancelet Branchiostoma californiense. A total of 48 specimens was also collected at an intertidal flat in the mid upper estuary. Of the 48 subtidal stations, only eight had B. californiense, and these sites all had a sand fraction above 72%. The remaining stations ranged in their sand content from as low as 1% to as high as 92%, with an average of 25.9%, with 29 stations having a sand content lower than 72%. Lower salinities and muddy sediments may limit the distribution of the lancelet further upstream. This information is useful when changes over decades in the ecology of the estuary need to be evaluated against the background of local, regional, and global dynamics. Rev. Biol. Trop. 58 (4): 1143-1148. Epub 2010 December 01.

Los cefalocordados están representados por los anfioxos, de los que especies del género Branchiostoma son los más conocidos. En los últimos años, estos organismos han sido muy estudiados, principalmente sus relaciones filogenéticas. Durante 1980, realizamos un muestreo del bentos en 48 estaciones del Golfo de Nicoya, costa Pacífica de Costa Rica y reportamos 265 ejemplares del anfioxo, Branchiostoma californiense. También recolectamos un total de 48 individuos en una planicie fangosa de la zona entre mareas de la región superior media del estuario. De las 48 estaciones solamente en ocho encontramos especímenes de B. californiense y estos sitios tenían un porcentaje de arena superior al 72%. Las otras estaciones tenían un porcentaje de arena en un ámbito tan bajo como 1% y tan alto como 92%, con un promedio de 25.9%, 29 estaciones presentaron un porcentaje de arena menor de 72%. Salinidades bajas y sedimentos fangosos pueden limitar la distribución del anfioxo en la región superior del estuario. Esta información es de utilidad cuando se desea evaluar los cambios en la biodiversidad y la ecología del estuario a largo plazo en el contexto de la dinámica local, regional o global.

On Branchiostoma californiense (Cephalochordata) from the Gulf of Nicoya estuary, Costa Rica.

The cephalochordates are represented by the lancelets, of which species of the genus Branchiostoma are the best known. In recent years, these organisms have been the center of activity of studies focusing on the phylogenetic relationships of the chordates. In 1980, a survey of the benthos at 48 stations in the Gulf of Nicoya estuary, Pacific coast of Costa Rica, yielded 265 specimens of the lancelet Branchiostoma californiense. A total of 48 specimens was also collected at an intertidal flat in the mid upper estuary. Of the 48 subtidal stations, only eight had B. californiense, and these sites all had a sand fraction above 72%. The remaining stations ranged in their sand content from as low as 1% to as high as 92%, with an average of 25.9%, with 29 stations having a sand content lower than 72%. Lower salinities and muddy sediments may limit the distribution of the lancelet further upstream. This information is useful when changes over decades in the ecology of the estuary need to be evaluated against the background of local, regional, and global dynamics.

Marine biodiversity of Costa Rica: Class Polychaeta (Annelida)

Un total de 332 especies de poliquetos pertenecientes a 50 familias han sido informados para Costa Rica con base en publicaciones. En unas pocas familias, el material disponible fue re-examinado y se hizo los cambios apropiados en la identificación de las especies. Solamente tres especies (Glycera oxycephala Ehlers, 1887; Hemipodia pustulata (Friedrich 1956); y Scolepis (Scolepis) squamata (Muller, 1806)) han sido reportados para la costa del Caribe de Costa Rica y estas especies también están presentes en la costa Pacifica. Las familias con más de 15 especies son: Spionidae (26), Cirratulidae (24), Nereididae (21 ), Lumbrineridae (19) y Paraonidae (16). No obstante el intenso esfuerzo de colecta hecho en la costa Pacífica durante los últimos 25 años, la fauna de poliquetos de Costa Rica, especialmente la de la costa Caribe, permanece poco conocida

Three hundred and thirty two species of polychaetes belonging to 50 families are reported for Costa Rica based on previously published reports. In a few families, available material was re-examined and appropriate changes in species identifications were made. Only three species, (Glycera oxycephala Ehlers, 1887; Hemipodia pustulata (Friedrich 1956); and Scolepis (Scolepis) squamata (Müller, 1806)) have been reported from the Caribbean coast of Costa Rica, and these three species have also been reported from the Pacific Coast. The families with more than 15 species are the Spionidae (26), Cirratulidae (24), Nereididae (21), Lumbrineridae (19) and Paraonidae (16). Despite extensive sampling on the Pacific coast over the last 25 years, the Costa Rican polychaete fauna, especially that of the Caribbean coast, remains poorly known

Marine biodiversity of Costa Rica: class Polychaeta (Annelida).

Three hundred and thirty two species of polychaetes belonging to 50 families are reported for Costa Rica based on previously published reports. In a few families, available material was re-examined and appropriate changes in species identifications were made. Only three species, (Glycera oxycephala Ehlers, 1887; Hemipodia pustulata (Friedrich 1956); and Scolepis (Scolepis) squamata (Miller, 1806)) have been reported from the Caribbean coast of Costa Rica, and these three species have also been reported from the Pacific Coast. The families with more than 15 species are the Spionidae (26), Cirratulidae (24), Nereididae (21), Lumbrineridae (19) and Paraonidae (16). Despite extensive sampling on the Pacific coast over the last 25 years, the Costa Rican polychaete fauna, especially that of the Caribbean coast, remains poorly known.

Capitellidae (Annelida: Polychaeta) from the Pacific Coast of Costa Rica

Eleven species of Capitellidae (Annelida: Polychaeta) belonging to eight genera are reported from the subtidal and intertidal of the Pacific Coast of Costa Rica. Three species, Mediomastus ambiseta, M. californiensis and Notomastus hemipodus, are found in highest abundances and are widespread in subtidal and intertidal environments. A taxonomic key to these species is included.

Some Nereididae (Annelida: Polychaeta) from the Pacific Coast of Costa Rica

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-Schrõder 1959 is removed from synonomy with L. culveri (Webster 1880) while Perinereis seridentata (Hartmann-Schrõder 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.

Marine biodiversity of Costa Rica: the phyla Sipuncula and Echiura

Fourteen species of Sipuncula belonging to 9 genera have been reported from Costa Rican waters, mostly from the Pacific coast. Three of these species are new records for Costa Rica (Phascolion strombus (Montagu 1804), Aspidosiphon (Aspidosiphon) muelleri Diesing 1851, and Aspidosiphon (Aspidosiphon) gracilis schnehageni (W. Fisher 1946)). One species of Echiura, Thalassema steinbecki Fisher 1946, in the order Echiuroinea, has been reported from the Pacific coast of Costa Rica.