Revision of Chaetacanthus Seidler, 1922 (Annelida, Phyllodocida, Polynoidae)

Zootaxa ◽  
2020 ◽  
Vol 4885 (3) ◽  
pp. 395-422
Author(s):  
PATRICIA SALAZAR-SILVA ◽  
DANIEL A. LÓPEZ-SÁNCHEZ ◽  
SERGIO I. SALAZAR-VALLEJO

The polynoid genus Chaetacanthus Seidler, 1922 currently includes three nominal species provided with parapodial branchiae. Members of this taxon have palps with longitudinal rows of papillae, notochaetae abundant and neurochaetae spinulose. Most Chaetacanthus species were originally described as belonging to Lepidonotus Leach, 1816, and some of them were later regarded as subjective synonyms of Iphione magnifica Grube, 1876, the type species for Chaetacanthus. This species was described from the Caribbean Sea and later recorded for the tropical Eastern Pacific. After the supposed Amphi-American distribution, a revision of all available material was performed in order to clarify the generic delineation, and to improve the understanding of species systematics. Further, some non-type specimens collected in Panama allowed us to have a better understanding of the variation of elytral shape and ornamentation along the body. The type material of Polynoe brasiliensis de Quatrefages, 1866 was examined and despite its poor condition, it shows parapodial branchial filaments which were overlooked in the original description; these branchiae are also present in the holotype of I. magnifica. We identify that there are no relevant difference between both species, and they are regarded as synonyms, and Chaetacanthus brasiliensis (de Quatrefages, 1866) is newly combined and is the senior synonym. On the other hand, Chaetacanthus pilosus (Treadwell, 1937), from the Eastern Pacific, and C. pomareae (Kinberg, 1856) from the South Central Pacific are redescribed, and C. harrisae n. sp., and C. ornatus n. sp. are both newly described from the Eastern Pacific. A key to identify all species of Chaetacanthus of the World, together with an appendix for the reversal of precedence of Lepidonotus Leach, 1816 over Eumolpe Oken, 1807 are also included. 

Author(s):  
Rafael Lemaitre ◽  
Ricardo Alvarez León

The Pacific coast of Colombia has been poorly explored, and its fauna is one of the least known in the tropical eastern Pacific. Although knowledge of the decapod fauna from this coast has recently increased, the information is scattered in numerous sources. A review of the literature showed that 378 decapods have been reported from this coast, including the islands of Gorgona and Malpelo. The numbers of species are distributed as follows; Dendrobranchiata, 18; Caridea,79; Thalassinidea, 13; Palinura, 6; Anomura, 61; and Brachyura, 201 .Twenty-seven species are known exclusively from the Colombian coast, three of which are endemic to the islands of Malpelo or Gorgona. A list of nominal species is presented, including information on distribution, important references, and synonyms under which the taxa have been reported for this coast. A summary of the history of explorations of the Pacific coast of Colombia as it relates to decapods, is presented. Zoogeographic affinities are briefly discussed for the marine species based on published distributions. Affinities are greatest with the Gulf of California (51.8%), followed by the Galápagos (28.6%), the Indo-Pacific (8.8%), and the Caribbean- Atlantic (7.7%).


1992 ◽  
Vol 6 ◽  
pp. 144-144
Author(s):  
Jeremy B. C. Jackson ◽  
Peter Jung

Molluscs are the most diverse and abundant tropical American macrofossils, but their distributions and evolution are not well understood. Classic studies by Olsson and Woodring documented a rich Late Miocene to Early Pliocene “Gatunian” fauna throughout the Caribbean and tropical Eastern Pacific, with many species in common between the oceans. This fauna was divided by formation of the Isthmus of Panama, and diverged into distinct Pacific and Caribbean faunas sometime thereafter. Diversity also decreased by about half in the Caribbean. However, the timing, rates and correlation of these major biological changes with changes in environmental conditions have not been resolved because of imprecise dating and taxonomy and failure to consider problems of sampling and biofacies in biological comparisons. We used the newly revised late Neogene stratigraphy for Panama and Costa Rica to date for the first time the radiation and extinction of molluscs on opposite sides of the Isthmus. Data include occurrences throughout tropical America for nearly 100 species of the Strombina-group (Gastropoda, Columbellidae) and for more than 500 gastropod and bivalve genera from 240 Late Miocene to Pleistocene isthmian collections.All evidence suggests that final closure of the Isthmus of Panama occurred between 3.5 and 2.5 My. Subgeneric divergence between the oceans was well developed, and trans-isthmian species were rare by the Early Pliocene, at least 2 Ma before final closure. Caribbean diversity remained high until 1.8 to 1.5 Ma when massive but selective extinction occurred. This was at least 1 Ma after final closure of the Isthmus, and may be correlated with onset of slightly cooler Caribbean sea surface temperatures in the Pleistocene. In contrast, Eastern Pacific diversity did not decline, and even increased during the Pleistocene.


2011 ◽  
Vol 24 (15) ◽  
pp. 3956-3970 ◽  
Author(s):  
Min Wen ◽  
Song Yang ◽  
Wayne Higgins ◽  
Renhe Zhang

Abstract During the boreal summer (June–August), vigorous convection appears over the eastern Pacific, southern Mexico, and northern South America, and oscillates on a distinct time scale of 10–20 days. Extended empirical orthogonal function (EEOF) analysis shows that the quasi-biweekly oscillation (QBWO) of the convection has two major modes: a west–east-orientated mode (WEM) and a north–south-orientated mode (NSM). The WEM, which is explained by the first two EEOF modes, originates over the eastern Atlantic, propagates westward along 15°N, and enhances over the Caribbean Sea before disappearing over the central Pacific. The NSM, explained by the third and fourth EEOF modes, originates over the western Pacific, moves eastward, and strengthens over the eastern Pacific. It shifts northward after arriving over the Caribbean Sea. Both modes have notable seasonal dependence, with the WEM more active in July and August and the NSM more active in June or earlier. The two distinct QBWO modes are linked to different rainfall patterns over the United States and Mexico. When the WEM is active in July and August, wet conditions occur over the southern central United States and dry conditions appear to the north. When the NSM is active in June, northern Mexico, the southwestern United States, the Missouri basin, and the northern Great Lakes are drier than normal, while southern Mexico and the eastern United States are wetter than normal. Significant variations in atmospheric circulation are found to be associated with the interannual variability of the NSM activity in June. However, these variations may not necessarily result from QBWO but, rather, provide a background for QBWO activity instead. In July and August, the association of QBWO with the precipitation pattern over North America may sometimes be related to hurricane activity.


Zootaxa ◽  
2021 ◽  
Vol 4970 (3) ◽  
pp. 495-514
Author(s):  
J. PABLO SÁNCHEZ-OVANDO ◽  
J. ROLANDO BASTIDA-ZAVALA

Pomatostegus Schmarda, 1861 is a serpulid genus with three recognized species, mostly from tropical waters. Pomatostegus stellatus (Abildgaard, 1789), was described from the Caribbean Sea, and has been widely recorded in the Pacific and Indian oceans; P. kroyeri Mörch, 1863 was described from Puntarenas, Costa Rica; however, most records from the Tropical Eastern Pacific were referred to P. stellatus. In this work, the two species are redescribed using morphological characters. The main differences are in the shape of the Spirobranchus-type collar chaetae, opercular plate shape and the number of “free” circlets of spines without accompanying of opercular plates. Comments about characters of P. actinoceras Mörch, 1863, described from Philippines, and an identification key for the three species, are included. 


Zootaxa ◽  
2010 ◽  
Vol 2375 (1) ◽  
pp. 1 ◽  
Author(s):  
PETER CASTRO ◽  
PETER K. L. NG

The family Euryplacidae Stimpson, 1871, traditionally included in the Goneplacidae MacLeay, 1838, is revised based on the examination of the type material of many of its species as well as unidentified and previously identified material from around the world. The revised family now consists of 31 species (including five that are described as new) belonging to 13 genera (including four that are described as new): Eucrate De Haan, 1835, with eight species, of which one is new; Euryplax Stimpson, 1859, with two species; Frevillea A. Milne-Edwards, 1880, with three species; Henicoplax n. gen., with five species of which three are new; Heteroplax Stimpson, 1858, monotypic; Machaerus Leach, 1818, with two species; Nancyplax Lemaitre, García-Gómez, von Sternberg & Campos, 2001, monotypic; Platyozius Borradaile, 1902, monotypic; Psopheticoides Sakai, 1969, monotypic; Systroplax n. gen., monotypic; Trissoplax n. gen., with two species, of which one is new; Trizocarcinus Rathbun, 1914, with two species; Villoplax n. gen., monotypic; and Xenocrate Ng & Castro, 2007, monotypic. The genus Platyozius and Eucrate formosensis Sakai, 1974, are removed from the synonymy of Eucrate and E. alcocki Serène, in Serène & Lohavanijaya, 1973, respectively. Neotypes are selected for Heteroplax dentata Stimpson, 1858, and Pilumnoplax sulcatifrons Stimpson, 1858, two species described from Hong Kong that have a confusing taxonomic history. A neotype is also selected for Euryplax nitida Stimpson, 1859, described from the Florida Keys. Seven nominal species described by other authors were found to be junior subjective synonyms for other species: Eucrate affinis Haswell, 1882, E. costata Yang & Sun 1979, E. haswelli Campbell 1969, and Pseudorhombila sulcatifrons var. australiensis Miers, 1884, of Trissoplax dentata (Stimpson, 1858); Galene laevimanus (Lucas, in Jacquinot & Lucas, 1853) of Eucrate dorsalis (White, 1849); Heteroplax nagasakiensis Sakai, 1934, of H. transversa Stimpson, 1858; and Pilumnoplax sulcatifrons Stimpson, 1858, of Eucrate crenata (De Haan, 1835). Eight euryplacid genera are exclusively found in the Indo-West Pacific region (except one species introduced in the Mediterranean), one is exclusive to each the Eastern Atlantic and Tropical Eastern Pacific regions, three to the Western Atlantic region, and one genus has both Western Atlantic and Tropical Eastern Pacific species.


Zootaxa ◽  
2010 ◽  
Vol 2684 (1) ◽  
pp. 36 ◽  
Author(s):  
LE–YANG YUAN ◽  
E ZHANG

Although Acrossocheilus kreyenbergii has been treated as a valid species since its original description, the type locality and identity of this species have hitherto remained uncertain. It is shown in this study that its precise location of ‘Tinghsiang’ or ‘Pinghsiang,’ the type locality of Gymnostoma kreyenbergii Regan, is the present Pingxiang City, Jiangxi Province, in the Gan Jiang, a tributary flowing to the Boyang Lake system, or in the Yangtze River drainage. Observation of the type specimens of this species and further comparison with those of other barred congeners reveal that G. kreyenbergii is in fact a senior synonym of Barbus cinctus Lin.


Zootaxa ◽  
2017 ◽  
Vol 4344 (3) ◽  
pp. 597
Author(s):  
GUILHERME MOREIRA DUTRA ◽  
IAGO DE SOUZA PENIDO ◽  
TIAGO CASARIM PESSALI ◽  
ANDRE LUIZ NETTO-FERREIRA

Curimatus albula Lütken 1874 was described from the Ribeirão da Mata at Lagoa Santa, a tributary of Rio das Velhas, Rio São Francisco basin. The species validity was questioned by Lütken (1875) himself, who suggested that the species could be a synonym of Curimatus gilbert Quoy & Gaimard, a species described from the Rio Macacu, a coastal river tributary of Guanabara bay, Rio de Janeiro. That synonymy was only formally proposed by Eigenmann (1910), and followed by most subsequent authors (e. g. Nielsen, 1974; Vari, 1992), except for Fowler (1975), who erroneously listed C. albula as the senior synonym of C. gilbert. Vari (1989) posteriorly removed both nominal species from Curimatus Oken (= Curimata Bosch) reallocating them in Cyphocharax Fowler, based on the lack of synapomorphic conditions present in other valid curimatid genera. Vari (1989) considered that those nominal species belonged to a major group within Cyphocharax also including C. grandocule Fernández-Yépez, C. modestus Fernández-Yépez, C. santacatarinae Fernández-Yépez, and C. voga Hensel, based on the presence of a rhomboidal caudal pigmentation and “random body spotting”. Later, Vari (1992) included C. grandocule along with C. albula in the synonymy of C. gilbert, and listed several characters allowing further distinction of that species from the remaining species of the group (i.e., number of vertebrae, scales in transverse series, and pigmentation characters). Among the characters involving the pigmentation pattern, Vari (1992) stressed the lack of randomly arranged dark spots on the lateral and dorsolateral surfaces of the body in C. gilbert (versus present in C. voga). 


2005 ◽  
Vol 19 (6) ◽  
pp. 557 ◽  
Author(s):  
Cinthya S. G. Santos ◽  
Fredrik Pleijel ◽  
Paulo Lana ◽  
Greg W. Rouse

Nereididae Johnston, 1865, part of the large clade Phyllodocida, is one of the best-known annelid groups. Presently, there are some 500 nominal species grouped into 42 genera, although there is little consensus among different authors as to how they should be classified. The relationships of nereidids were assessed in a morphology-based parsimony analysis of 41 terminal taxa, with members of Chrysopetalidae and Hesionidae used as outgroups. Type species for the majority of currently recognised nereidid genera were used as terminal taxa, and character information was based on examination of type and non-type specimens, together with literature descriptions. High degrees of homoplasy were found for several features that are traditionally applied to delineate subgroups of Nereididae, including the presence of paragnaths and the distribution of different kinds of chaetae. Six major groups were recovered: Namanereidinae, including Namalycastis and Namanereis, characterised by spherical shape of palpostyles and ventrally displaced notoaciculae; one clade corresponding in part to previous authors concepts of Nereidinae, including Nereis, Eunereis, Hediste and Platynereis (the relationships of several well known nereidids, such as Neanthes and Perinereis, commonly referred to Nereidinae, could not be unambiguously resolved); one unnamed and not previously recognised clade (A), including Australonereis, Laeonereis, Dendronereides and Olganereis, characterised by the presence of papillae on the maxillary ring; a second unnamed clade (B), including Leptonereis, Sinonereis, Tylonereis and Tylorrhynchus, characterised by enlarged notopodial ligulae; a well supported Gymnonereidinae, restricted to Ceratocephale, Gymnonereis, Tambalagamia and Micronereides; and a third unnamed clade (C), including Ceratonereis, Solomononereis, Unanereis, Cheilonereis and Websterinereis, characterised by unilobated neuropodial postchaetal lobes. Among these groups we found good support for the Namanereidinae, the Gymnonereidinae and for the whole of Nereididae. The subfamilies Dendronereidinae and Notophycinae (based on Micronereis, senior synonym of Notophycus) are regarded here as monotypic.


Author(s):  
Rudo Von Cosel

This paper deals with the moDusk species known from the Ciénaga Grande de Santa Marta and from the littoral zone and the upper continental shelf of the coastal strip between lala de Salamanca and the balneario El Rodadero (Caribbean coast of Colombia, South America). 468 species and subspecies ofmarine, brackish-water and freshwater mollusks are reponed comprising 211 bivalves. 6 scaphopods and 251 gastropods. 101 species and 1 subspecies have been found in the Ciénaga Grande (most of them also in the sea), a further 9 marine species have been recorded only as old shells in the estuarine part of the Ciénaga Grande, the rest have been collected exclusively in the marine part of the investigated area. 268 species (120 bivalves, 3 scaphopods and 145 gastropods) have been live-collected, the remainder only as empty shells. 165 species and 9 subspecies (90 + 1 bivalves and 75 + 2 gastropods) are monographed and discussed in detail, among them 98 species and 1 subspecies (48 bivalves and 50 + 1 gastropods) from the Ciénaga Grande or its estuarine región, and 67 species and 2 subspecies only from the sea. Of the 98 species from the Ciénaga Grande, 64 have been live-collected, tlte oth*er 34 as empty shells only. The Ciénaga Grande de Santa Marta is the largest coastal lagoon of the Caribbean coast of Colombia, occupying an area of 450 km'. According to the season, drastic changes in salinity of between 0 and S0*/oo may be observed. Depth varies between 1 and 2.5 m, and the shore mostly consists of mangrove swamps. The bottom is muddy, some more or less extended areas having oyster reefs or shell concentrates. There are small areas in the northern part with sandy bottoms. Most mollusk species enter the lagoon and spread out within it as planktonic larvae by means of the currents, if conditions are favourable. Only very rarely are adult snails able to enter {he Ciénaga Grande actively. The propagation of the planktonic larvae within the lagoon depends on the nearest natural occurrence of the species, the duration of the pelagic phase, settlement depends on the presence of suitable substrate (besides the other ecological conditions needed). On account of finding older empty shells in a relative uniform state of preservation throughout the whole basin of the Ciénaga Grande, and of species not having been encountered there live, it can be assumed that there had previously existed an extremely long period of high salinity in the lagoon, with lower amplitudes than nowadays. According to C dates this period can be located ¿00-360 years ago, and its duration is estimated at at lea»t 3.5 years. The reason for this was most probably the greater interchange of sea and lagoonal water through several no longer existing, but still traceable, inlets. The zoogeographic division of those species treated in detail (except the freshwater species) is as follows: western Atlantic species. 68; Caribbean species. 48: southern Caibbean species, partly also from Brasil, 39. Í2 species are amphi-atlantic and 5 amphi-american. Six species known from Suriname, Venezuela or Brasil are recorded for the first time from Colombia and the southwestern Caribbean. 69 species have a win species (cognate species) existing in the Eastern Pacific (Panamic zoogeographic province). The portion of species with Pacific twin species found in the studied area is very high in comparison with other regions of the Caribbean, especially among the bivalves. This is due most probably to the similarity of the biotopes on large parts of the Colombian Caribbean coast and the tropical Eastern Pacific coast, preferred by these species.


Sign in / Sign up

Export Citation Format

Share Document