New ecological and taxonomic remarks on Sabinella troglodytes and Nanobalcis worsfoldi (Gastropoda: Eulimidae) living on the “slate-pencil sea urchin” from the Mexican Caribbean region

Abstract Eulimidae is one of the most diversified families among marine parasitic gastropods. They are usually reported associated with echinoderms, but for most described species the host is unknown, and few biological aspects of the symbiosis are known. As part of a larger study on eulimids, 300 sea urchins were collected in shallow water reef lagoons. Some were kept alive in the laboratory for 1 week and photographed and filmed under stereomicroscopes. Nanobalcis worsfoldi lives around and at the base of primary spines of the sea urchin Eucidaris tribuloides and is very abundant, whereas Sabinella troglodytes lives attached inside a gall that it builds from primary spines, and is uncommon. A complete characterization of the shells and morphology data for both eulimids are included. The comparison of our specimens with type and non-type material indicates several noteworthy features. We found higher and wider whorls, variation in position of growth scars and total number of whorls. We suggest that there is a species complex for Sabinella troglodytes. Mantle pigmentation patterns, mode of attachment, live displacement, and other ecological observations on the host are presented for the first time for both species from the Mexican Caribbean Sea. Keywords: Ectoparasites; Echinoderms; Eucidaris; Shallow water; Symbiosis Resumen Eulimidae es una de las familias más diversificadas entre los gasterópodos marinos parásitos. Por lo general, se reportan asociados con equinodermos, pero para la mayoría de las especies descritas, el huésped es desconocido y pocos aspectos biológicos de la simbiosis son conocidos. Como parte de un estudio más amplio sobre eulímidos, se recogieron 300 erizos de mar en lagunas arrecifales de aguas poco profundas, algunos se mantuvieron vivos en el laboratorio durante una semana y fueron fotografiados y filmados bajo el microscopio estereoscópico. Nanobalcis worsfoldi vive alrededor y en la base de las espinas primarias del erizo de mar Eucidaris tribuloides y es muy abundante, mientras que Sabinella troglodytes, vive adherido dentro de una agalla que construye en las espinas primarias y es poco común. Se incluye una caracterización completa de los datos de conchas y morfología para ambos eulímidos. La comparación de nuestros especímenes con material tipo y no-tipo, reveló varias características notables. Encontramos la vuelta principal del cuerpo más alta y más anchas, variación en la posición de las cicatrices de crecimiento y el número total de vueltas. Sugerimos que existe un complejo de especies para Sabinella troglodytes. Los patrones de pigmentación del manto, el modo de adherirse, desplazamiento en vivo y otras observaciones ecológicas en el huésped se presentan por primera vez para ambas especies del mar Caribe mexicano. Palabras clave: Ectoparásitos; Equinodermos; Eucidaris; Agua poco profunda; Simbiosi

Pycnogonids associated with the giant lion´s-paw scallop Nodipecten subnodosus (Sowerby) in Ojo de Liebre Bay, Guerrero Negro, Baja California Sur, Mexico

Five species of epibenthic pycnogonids collected on the giant lion´s-paw scallop Nodipecten subnodosus are recorded. A new species of Eurycyde, E. bamberi, is described. Of the 19 species known in this genus; the new species is closest to E. hispida Kroyer, 1844 but differs from it in the absence of plumose spines and the shapes of the lateral process, first coxa, and ocular tubercle. The new species represents the third member of Eurycyde from the eastern Pacific in addition to E. spinosa Hilton, 1916 and E. clitellaria Stock, 1955. Besides E. bamberi, the following species were collected: Nymphopsis duodorsospinosa Hilton, 1942c; Callipallene californiensis (Hall, 1913); Nymphon lituus Child, 1979; and Pycnogonum rickettsi Schmitt, 1934. Pycnogonum rickettsi is recorded for first time from Mexican waters, as is Nymphon lituus from the western coast of Baja California Peninsula. Each of these four species are re-described and re-illustrated in order to fill in existing gaps in the literature of the region

A new species of Websterinereis from the Gulf of California and redescription of Websterinereis foli (Fauvel, 1930) (Annelida, Nereididae)

A new species of Websterinereis Pettibone, 1971, W. pettiboneae sp. n. is described from La Paz Bay, Gulf of California, Mexico. This species is similar to W. foli (Fauvel, 1930) in the neuropodial falcigers shape, but can be separated by the tentacular cirri length, notopodial prechaetal lobe shape, and the size of the notopodial dorsal and ventral ligules on posterior parapodia. Websterinereis foli is redescribed based upon type material. Additional observations on the inter-annual density variation of W. pettiboneae sp. n. during a four-year study are also provided. A key to all species of Websterinereis is included

Relocation of Dodecaseta McCammon & Stull, 1978 (Annelida, Capitellidae) in Notodasus Fauchald, 1972

The capitellid polychaete genus Dodecaseta McCammon & Stull, 1978 is relocated in Notodasus Fauchald, 1972. Two species are redescribed based on examination of type material and three new combinations are proposed: Notodasus oraria (McCammon & Stull, 1978), N. eibyejacobseni (Green, 2002). N. fauchaldi (Green, 2002). N. kristiani (García-Garza et al., 2009), is synonymized under N. oraria. Some comments on Dasybranchus lumbricoides Grube, 1878 are include

A new species of Amphictene (Annelida, Pectinariidae) from the Gulf of Mexico, with a redescription of Amphictene guatemalensis (Nilsson, 1928)

The genus Amphictene is reported for the first time from Mexico. Previous records for America are restricted to Brazil (A. catharinensis) (Grube, 1870), and Guatemala (A. guatemalensis) (Nilsson, 1928). In this paper we describe a new species, Amphictene helenae sp. n., characterized by the presence of three pairs of tentacular cirri, while other species have only two pairs. The new species is closely similar to Amphictene catharinensis, and can be distinguished by the presence of a circular group of glandular papillae inserted between the lines of glandular cirri present from the second segment. A. guatemalensis is redescribed based on type material; it differs from the new species in the presence of two pairs of tentacular cirri on segments 1 and 2, six pairs of glandular cirri on the third segment, and four glandular lobes fused in pairs on the fourth segment

New Echinoid (Spatangoida: Toxasterinidae) from the Campanian of Coahuila, Northeastern Mexico

ABSTRACT Three specimens corresponding to a new echinoid species from the Upper Cretaceous (Lower Campanian) from Austin Formation in the northeastern of Mexico are reported here. The morphology of the specimens (test with a cordiform aboral region) as well as the sedimentary environment reported at the Austin Formation, suggests that this species represents an infaunal and detritivorous dweller living in a shallow water environment within the continental shelf. This is consistent with the more actual knowledge for other species of Diplodetus Keywords: Echinoids, Diplodetus, Upper Cretaceous, Campanian, Austin Formation, NE Mexico. ESUMEN Se reportan tres especímenes de Diplodetus brisenoi, una nueva especie de equinoideo del Campaniano Inferior (Cretácico Superior) de la Formación Austin, en Jiménez, Coahuila, noreste de México. Tanto su morfología (testa con ámbito cordiforme) como el ambiente de depósito reportado para la Formación Austin sugieren que esta especie representa un elemento de la infauna con hábitos detritívoros en ambientes de plataforma, lo cual es consistente con lo reportado para otras especiesdel género Diplodetus. Palabras clave: Equinoideos, Diplodetus, Cretácico Superior, Campaniano, Formación Austin, NE de México

Re-description of Parasphaerosyllis indica Monro, 1937 (Annelida, Syllidae), with the establishment of a new species from western Mexico

Parasphaerosyllis Monro, 1937 is a syllid genus, currently composed of four species: P. indica Monro, 1937 from the Arabian Sea, P. uschakovi (Chlebovitsch, 1959) from the Kurile Islands, P. ezoensis Imajima & Hartman, 1964 from Japan and P. malimalii Capa, San Martín & López, 2001 from the Pacific coast of Panama. The distribution of P. indica is circum-tropical to temperate waters, but the presence of species complexes has been suggested. In order to clarify the distribution of P. indica in many areas of the world, a re-description, based on examination of the type material, is required as a first step to a better understanding of its diagnostic features.Parasphaerosyllis indica is re-described, based on holotype examination, a new species is established from the Gulf of California and Parasphaerosyllis malimalii is reported for the first time since its description in 2001. Parasphaerosyllis irregulata sp. nov. is distinguished from its congeners by the following features: 1) Palps are free at their base; 2) Two types of dorsal cirri are present: spherical to bulbous and moniliform cirri; 3) Both types of cirri are distributed irregularly. A spherical/bulbous and moniliform cirrus may appear together within the same segment (asymmetrical segment) or only a spherical/bulbous cirrus may appear in several consecutive segments (not alternating as occurs in congeners); 4) The spherical/bulbous cirri may have distal knobs with 1–3 terminal articles; and 5) Bidentate falcigers with short, sub-triangular blades with a proximal tooth slightly larger that the distal one. A taxonomic key to species of Parasphaerosyllis species is included

New records of polychaetes (Annelida) for northern Ecuador

Even though Ecuador is one of the twelve mega-diverse countries in the world, the polychaetes are still poorly known. Twelve polychaete species, namely Hemipodia pustatula (Glyceridae); Microphthalmus arenarius (Hesionidae); Scoletoma zonata (Lumbrineridae); Nereis riisei, Pseudonereis gallapagensis (Nereididae); Armandia salvadoriana, Euzonus mucronata (Opheliidae); Phyllodoce multiseriata (Phyllodocidae); Pisione longispinulata (Pisionidae); Malacoceros indicus, Scolelepis (Scolelepis) acuta (Spionidae) and Opisthosyllis arboricola (Syllidae) are newly reported in the intertidal sandy beaches of Bunche (0839′ 01.98′′N 80803′ 55.01′′W) and Cabo San Francisco (0838′ 16.35′′N 80803′ 14.07′′W), Esmeraldas Province (Ecuador). Furthermore, an amended diagnosis of Pisione longispinulata is presented

Generic revision of Notodasus Fauchald, 1972 (Polychaeta: Capitellidae) with descriptions of four new species from the coasts of Mexico

RESUMEN Revisión del género Notodasus Fauchald, 1972 (Polychaeta: Capitellidae) con la descripción de cuatro nuevas especies de las costas de México. – Se enmienda el género Notodasus Fauchald, 1972 y se redescriben las especies que lo forman. Las descripciones originales de N. magnus Fauchald, 1972, N. dexterae Fauchald, 1973 y N. arenicola HartmannSchröder, 1992 o bien eran incompletas o bien incluyen errores, por lo que dichas especies se redescriben en base al material tipo. Además, se describen cuatro nuevas especies en base a especimenes recolectados en localidades tropicales de México: Notodasus harrisae n. sp., N. hartmanae n. sp., N. kristiani n. sp. y N. salazari n. sp. Se han realizado descripciones estandarizadas para todas las especies, las cuales incluyen el patrón de tinción con verde de metilo, la textura del epitelio y la forma de los ganchos encapuchados. Finalmente, se incluye una clave de todas las especies descritas del género. ABSTRACT The capitellid genus Notodasus Fauchald, 1972 is emended and its previously known species are redescribed. Since the original descriptions of N. magnus Fauchald, 1972, N. dexterae Fauchald, 1973, and N. arenicola Hartmann-Schröder, 1992 omitted important morphological details and were either incomplete or misleading, these species are redescribed based upon examination of type materials. Four new species are described from tropical localities in Mexico: Notodasus harrisae n. sp., N. hartmanae n. sp., N. kristiani n. sp. and N. salazari n. sp. Standardised descriptions are provided for all species including the methyl green staining pattern, the epithelial texture and the shape of hooded hooks. A key for all described species is provided

Catalogue of type specimens deposited in the Polychaeta Collection of the Universidad Autónoma de Nuevo Léon (Mexico)

In Mexico, there are six scientific collections of polychaetous annelids. The "Colección Poliquetológica" from the Universidad Autónoma de Nuevo León houses one of the three most important collections of annelids in the country, based on a number of lots and number of type materials deposited, as well as geographical coverage.A catalogue of type materials of polychaete annelids housed at the “Colección Poliquetológica” from the Universidad Autónoma de Nuevo León (México) is presented for the first time. The Collection contains 37 holotypes, 174 paratypes and one syntype. These type materials are grouped in 15 families, 35 genera and 54 species of marine worms. Types were described mostly from the Mexican waters, with a low number of types from Ecuador, El Salvador, Argentina, USA, Philippines, New Caledonia and Japan