Integrative taxonomy unravels the species diversity of Parachristianella (Cestoda : Trypanorhyncha) from both sides of the Panamanian isthmus

2018 ◽  
Vol 32 (2) ◽  
pp. 278 ◽  
Author(s):  
Bjoern C. Schaeffner ◽  
Fernando P. L. Marques

The uplift of the Panamanian isthmus in the Pliocene caused the termination of gene flow among members of many ancestral populations of marine lineages leading the diversification of geminate species confined to opposite sides of Central America. This palaeogeographical event has been evoked to explain the diversification of few lineages of batoids with trans-isthmian distribution. As such, there is the expectation that this vicariance event also affected lineages of parasites associated with them. Our study suggests that this event can explain the diversification of Parachristianella Dollfus, 1946 (Trypanorhyncha:Eutetrarhynchidae) in the Caribbean Sea and tropical eastern Pacific Ocean. We provide molecular, morphological and biogeographical evidence to recognise five lineages within this genus inhabiting the coastal waters of Panama, including P. parva Campbell & Beveridge, 2007 and four new species: P. mendozai, sp. nov., P. kuchtai, sp. nov., P. campbelli, sp. nov. and P. soldanovae, sp. nov. These species can be diagnosed by unambiguous sets of molecular characters. The morphological cohesiveness of sister species, which most likely diverged from around 3million years ago through the uplift of the Panamanian isthmus, suggests that the traditional emphasis on the tentacular armature to circumscribe species within trypanorhynchs might underestimate the diversity of recently diverged lineages.

Author(s):  
Denis H. Lynn ◽  
Guy L. Gilron

Fifteen marine strombidiid species were measured and identified after protargol staining of bottle-cast samples collected during an annual study of the ciliate microzooplankton in the Caribbean Sea. Nine of these are described herein as new species. One new species from the genus Tontonia, T. simplicidens sp. nov., is defined, based on the pattern of the girdle and ventral kinety. Six new species of Strombidium, S. bilobum sp. nov., S. eurystomum sp. nov., S. ioanum sp. nov., S. maedai sp. nov., S. pollostomum sp. nov. and S. sphaericum sp. nov. are defined, based on cell size and shape, the arrangement of the oral ciliature, and the nature of the macronucleus. One new strombidiid genus Cyrtostrombidium gen. nov., is defined by the presence of a unique oral ‘basket’ and the absence of the ventral polykinetidal zone. Two species of Cyrtostrombidium, C. longisomum sp. nov. and C. wailesi sp. nov., are distinguished, based on cell size and macronuclear structure. Assemblages of six previously-described strombidiid species, S. constrictum, S. dalum, S. epidemum, S. inclinatum, S. wulffi, and Laboea strobila are also briefly described.


Author(s):  
Lina M. Ramos Ortega ◽  
Luís A. Vidal V.

Three species of the genus Heterodinium Kofoid are reported for the first time in coastal waters of the Colombian Caribbean. The identified species are Heterodinium rigdenae Kofoid, 1906, Heterodinium agassizii Kofoid, 1907 and Heterodinium angulatum Kofoid y Michener, 1911. Information about distribution of these species in the Caribbean Sea and the Gulf of Mexico is given.


2016 ◽  
Author(s):  
Ana María Durán-Quesada ◽  
Luis Gimeno ◽  
Jorge Amador

Abstract. A climatology of moisture sources linked with Central American precipitation was computed based upon Lagrangian trajectories for the analysis period 1980–2013. The response of the annual cycle of precipitation in terms of moisture supply from the sources was analysed. Regional precipitation patterns are mostly driven by moisture transport from the Caribbean Sea (CS). Moisture supply from the Eastern Tropical Pacific (ETPac) and Northern South America (NSA) exhibits a strong seasonal pattern but weaker compared to CS. The regional distribution of rainfall is largely influenced by a local signal associated with surface fluxes during the first part of the rainy season, whereas large scale dynamics forces rainfall during the second part of the rainy season. The Caribbean Low Level Jet (CLLJ) and the Chocó Jet (CJ) are the main conveyors of regional moisture, being key to define the seasonality of large scale forced rainfall. Therefore, interannual variability of rainfall is highly dependent of the regional LLJs to the atmospheric variability modes. The El Niño-Southern Oscillation (ENSO) was found to be the dominant mode affecting moisture supply for Central American precipitation via the modulation of regional phenomena. Evaporative sources show opposite anomaly patterns during warm and cold ENSO phases, as a result of the strengthening and weakening, respectively, of the CLLJ during the summer months. Trends in both moisture supply and precipitation over the last three decades were computed, results suggest that precipitation trends are not homogeneous for Central America. Trends in moisture supply from the sources identified show a marked north-south seesaw, with an increasing supply from the Caribbean Sea to northern Central America. Long term trends in moisture supply are larger for the transition months (March and October). This might have important implications given that any changes in the conditions seen during the transition to the rainy season may induce stronger precipitation trends.


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. 


2010 ◽  
Vol 23 (5) ◽  
pp. 1175-1188 ◽  
Author(s):  
Matías Méndez ◽  
Víctor Magaña

Abstract Major prolonged droughts in Mexico during the twentieth century are mainly related to anomalous dry summers, such as those observed in the 1930s, the 1950s, or the 1990s. Droughts in northern Mexico frequently coincide with anomalously wet conditions over Mesoamerica (i.e., southern Mexico and Central America), and vice versa, displaying a dominant “seesaw” structure in persistent precipitation anomalies, mostly in relation to tropical sea surface temperature (SST) anomalies. A warmer North Atlantic Ocean, expressed as a positive phase of Atlantic multidecadal oscillation (AMO), is related to the occurrence of major droughts in North America associated with weaker-than-normal moisture flux into northern Mexico. Drought over northern Mexico may also be related to changes in transient activity in the Caribbean Sea. During the negative phase of the Pacific decadal oscillation (PDO), the Caribbean low-level jet (CLLJ) weakens and easterly wave (EW) activity increases, leading to more tropical convection over Mesoamerica and less moisture flux into northern Mexico. On the other hand, when EW activity is weak over the intra-Americas seas (IAS) (i.e., the Gulf of Mexico and the Caribbean Sea) because of a stronger-than-normal CLLJ, precipitation increases over northern Mexico. Therefore, the interaction between easterly waves and the trade winds over the IAS appears to be crucial to explain the spatial patterns of droughts that have affected Mexico. In addition, low-frequency modulators, such as AMO or PDO, may serve to explain the spatial patterns of severe prolonged droughts in Mexico during the nineteenth century.


PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e18994 ◽  
Author(s):  
Rafael de la Parra Venegas ◽  
Robert Hueter ◽  
Jaime González Cano ◽  
John Tyminski ◽  
José Gregorio Remolina ◽  
...  

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1120
Author(s):  
Wilmar L. Cerón ◽  
Mary T. Kayano ◽  
Rita V. Andreoli ◽  
Alvaro Avila-Diaz ◽  
Itamara Parente de Souza ◽  
...  

This study analyzes the variability of the Choco jet (CJ) and Caribbean low-level jet (CLLJ) with consideration of the simultaneous Pacific interdecadal oscillation (PDO) and Atlantic multidecadal oscillation (AMO) low-frequency mean states and their effects on the atmospheric circulation and rainfall in northwestern South America and Central America for the 1900–2015 period, during the seasons with the highest intensities of the CJ (September–November (SON)) and the CLLJ (June–August). Variations in the sea surface temperature (SST) anomaly positioning in the eastern Pacific, tropical North Atlantic (TNA)/Caribbean Sea during different mean states restrict the anomalous circulation, and, consequently, the intensity of the CJ and CLLJ. During the warm AMO (WAMO)/cold PDO (CPDO), the SST gradient from the tropical Pacific into the TNA, accompanied by a cyclonic circulation near the east coast of the Americas, intensifies the west–east circulation in the region, strengthening the CJ and weakening the CLLJ during SON such that rainfall increases over Colombia, Central America and in adjacent oceans. During the cold AMO (CAMO)/warm PDO (WPDO) phase, a relative east/west SST gradient occurs in TNA, consistent with a cyclonic circulation in western TNA, establishing an anomalous southwest–northwestward circulation from the eastern Pacific into the Caribbean basin, forming a well-configured CJ, increasing precipitation over Central America and its adjacent oceans. For the CLLJ, during CAMO phases, the anticyclonic circulations extended over most of the TNA favor its intensification from 30° W to the Caribbean Sea. In contrast, during WAMO, the cyclonic circulation near the east coast of the United States restricts its intensification to the Caribbean Sea region. To the best of our knowledge, the results presented here are new and might be useful in atmospheric modeling and extreme event studies.


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