Historical biogeography and distribution of the freshwater cyclopine copepods (Copepoda, Cyclopoida, Cyclopinae) of the Yucatan Peninsula, Mexico

Aim To determine and analyse the distribution of the freshwater cyclopine copepod fauna of the Yucatan Peninsula (YP) and its relationship with the geological and climatic history of this Neotropical karstic zone. Location The Yucatan Peninsula, Mexico. Methods Plotting of georeferenced sites, analysis of local and regional geological and climatic history, analysis and comparison of regional and local faunistic records. Results Distinct dispersal and/or vicariant processes seem to be linked to the current distributions of the seven genera known in the YP. In general, the endemic hypogean or benthic crevicular forms (i.e. Diacyclops chakan, D. puuc and Mesocyclops chaci), derived from epigean, tropical, widely distributed forms (some of them South American) may have been among the earliest colonizers of the subterranean habitats in the YP. The distribution of these and other endemic forms seem to be related to the Holocene dry periods that desiccated the largest bodies of water and isolated local populations of different species. These vicariant processes resulted in forms with restricted distributional areas; some of these formed sister species that speciated in geographically close localities but related to a common identifiable ancestor. Overall, the processes of cyclopine colonization of the YP show the influence of the South American fauna, as the closest relatives of some species endemic to the YP are South American forms; the Nearctic influence is low. The cyclopine fauna of the YP is formed by a mixture of Nearctic‐derived (species of Acanthocyclops), Neotropical (i.e. M. edax, M. longisetus, A. panamensis, Thermocyclops inversus and T. tenuis), and epigean and hypogean endemic forms. The highly dynamic geomorphology of the YP and the recent climatic changes in the Holocene define the YP as a peculiar subregion that harbours a diverse fauna of cyclopine copepods with a high endemism. Main conclusion The current distribution of cyclopine copepods reflects relatively recent, post‐Pliocene biogeographical patterns; probably older patterns are involved as well. The eastern coast of the Yucatan is the most recently colonized by cyclopine copepods. Most of the genera are linked with South American forms, and the Nearctic influence is weakly represented. This group has no marine relatives, but there is evidence of vicariant events involving cave‐dwelling forms.     

Diversity and distribution of freshwater copepods (Crustacea) in southeastern Mexico

Plankton and littoral samples were obtained from several ponds and lagoons of different environments in the Mexican state of Tabasco. These systems are located in the Grijalva-Villahermosa or the Usumacinta basins. Twenty-two copepod species were recorded, most of them cyclopoids with neotropical and Caribbean affinities. Physical and chemical data associated with the species, as well as morphometric parameters of the surveyed systems were measured and analyzed. A correlation was found between diversity and parameters related to the productivity and the shoreline development (D _L) of the systems; therefore the littoral heterogeneity could be used to predict the species number in shallow tropical systems. At a regional level, the Tabasco copepod fauna is similar to that known from the Yucatan Peninsula, but different from the faunal associations of central Mexico. Distributional patterns differed slightly between both basins and appear to be correlated with climatic variations. This first survey of the freshwater copepod fauna in the state of Tabasco shows it to be constituted mainly by neotropical forms.     

Global diversity of copepods (Crustacea: Copepoda) in freshwater

The zoogeographic distributions of the 2,814 species of copepods reported from freshwater are analysed. Faunal diversity is compared between zoogeographic regions: the Palaearctic region has more than double the species richness of the next most diverse region, the Neotropical. Historical factors affecting levels of diversity are identified. More than 90% of all freshwater copepods are endemic to a single-zoogeographic region and endemic genera occur in all regions except Antarctica. Species that are not endemic to a single region include the highly vagile and cosmopolitan species occurring in four or more regions. The greatest faunal connectivity, as identified by Sørensen’s Index, is between Palaearctic and Nearctic regions, and identifies the Holarctic taxa. Key human-related issues, such as the role of copepods as vectors for human parasites and the losses caused by parasitic copepods in commercial aquaculture, are mentioned.     

The calanoid fauna (Crustacea,Copepoda) of the Cordillera Oriental of the Colombian Andes

Calanoid copepods belonging to four species and one subspecies from lakes and ponds mainly from the Cordillera Oriental (22) and Cordillera Central (1) of the Colombian Andes are recorded. Most of the water bodies studied are located in the páramo region, between 2996 and 4085 m altitude. The family Boeckellidae is recorded for the first time from Colombia. Taxonomic characteristics of Boeckella occidentalis Marsh, 1906, Boeckella gracilis (Daday,1902) and the diaptomid Prionodiaptomus colombiensis (Thiébaud, 1914) are discussed. A new diaptomid genus, Colombodiaptomus, with one species and one subspecies are established.     

Historical biogeography of the Yucatan Peninsula,Mexico: a perspective from ferns (Monilophyta) and lycopods (Lycophyta)

Based on known data sets and maximum entropy distribution data of fern and lycopod species registered in the Yucatán Peninsula, track and parsimony analyses were undertaken to evaluate the contribution of these groups to the establishment of biogeographical relationships of the peninsula with other areas. The resulting generalized tracks clearly agree with the geological origin of the peninsula and the previously recognized relationship with the Greater Antilles is not supported for ferns and lycopods. Instead, a Central American generalized track connects the Yucatán Peninsula with south‐eastern México and Central America. Floristically, the peninsula harbours 66 species of ferns and lycopods. Seven are registered for the first time in the Yucatán Peninsula and one is a new species for México. These species do not follow the latitudinal pattern expected if ecological factors, such as humidity and rainfall, were the most important in determining their distributions. Groups of areas recognized with parsimony analysis of endemicity could not be defined as provinces as a result of the lack of endemic species. Nevertheless, a regionalization scheme based on maximum entropy distribution data and supported by track analyses is proposed. Two separate districts are recognized within the Yucatán Peninsula: arid/dry Yucatán in the north and El Petén (humid) in the south. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 775–786.     

A new species of Metacyclops Kiefer, 1927 (Copepoda,Cyclopidae, Cyclopinae) from the Chihuahuan desert,northern Mexico

A new species of the freshwater cyclopoid copepod genus Metacyclops Kiefer, 1927 is described from a single pond in northern Mexico, within the binational area known as the Chihuahuan Desert. This species belongs to a group of Metacyclops species with a 3443 spine formula of swimming legs. It is morphologically similar to Metacyclops lusitanus Lindberg, 1961 but differs from this and other congeners by having a unique combination of characters, including a caudal rami length/width proportion of 3.5–3.8, a innermost terminal seta slightly longer than the outermost terminal seta, intercoxal sclerites of legs 1-4 naked, a strong apical spine of the second endopodal segment of leg 1 and one row of 6-8 small spinules at the insertion of this spine. The finding of this species represents also the first record of the genus in Mexico and the third in North America, where only two other species, Metacyclops gracilis (Lilljeborg, 1853)and Metacyclops cushae Reid, 1991 have been hitherto reported. This is also the first continental record of a species of Metacyclops from an arid environment in the Americas. This species appears to be endemic to the Chihuahuan Desert, thus emphasizing the high endemicity of this area.     

The freshwater zooplankton of Thailand (Rotifera and Crustacea)

A list is given of all zooplankton species hitherto reported from Thailand, based on the author's own observations and on the literature.From a comparison with the fauna of some neighbour countries, it appears that important gaps remain to be filled-in.     

An outline of the distribution patterns of the freshwater Copepoda of Israel and surroundings

The distribution of the freshwater Copepoda in the Levantine province is analyzed. The characteristics of the five subprovinces of the freshwater fauna in the area are briefly presented and the representative species of Copepoda, mainly of the Harpacticoida, are mentioned. The presence of a palearctic enclave in the mountains of South Sinai and the presence of Ethiopian species in the Jordan-Dead Sea valley, is emphasized.     

Biogeographical analysis of two Polypodium species complexes (Polypodiaceae) in Mexico and Central America

We analyzed the geographical and elevational distributions of two Polypodium complexes from Mexico and Central America. Distribution data of nine species of the Polypodium colpodes complex and the Polypodium plesiosorum complex were obtained from almost 1500 herbarium specimens, field collections in Mexico and Costa Rica, and literature studies. The presence of each species was recorded for each Mesoamerican country, in 1° × 1° grid‐cells and biogeographical provinces. The rarity of species was also evaluated. Although the two complexes show extensive overlap, the P. colpodes complex is distributed mainly along the Pacific versant of Mexico and Central America, whereas the P. plesiosorum complex occurs mainly along the Atlantic versant. Those biogeographical provinces with maximum species diversity are Chiapas (seven species), Sierra Madre del Sur (six species), and the Trans‐Mexican Volcanic belt (six species). Grid‐cells with more species are located mainly in the mountains of central‐southern Mexico and northern Central America. Richness does not decrease or increase with latitude. Elevation distributions showed that most Polypodium species are concentrated in the montane interval and three species groups were recognized based on elevational preferences. Polypodium colpodes and P. plesiosorum are the most widely distributed species, whereas Polypodium castaneum and Polypodium flagellare are the only two species that possess the three attributes of rarity (narrow geographical distribution, high habitat specificity, and scarce local populations). Polypodium species of both complexes are present mainly in the montane regions of the study area and show some degree of geographical sympatry, especially in southern Mexico and northern Central America. This overlapping is explained by the elevation tolerance within montane systems and because most species inhabit three or more vegetation types. The distributional patterns of these complexes coincided with the three regional highlands of Mesoamerica, which are separated from each other by the Isthmus of Tehuantepec and by the lowlands of Nicaragua. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

The freshwater Copepoda (Crustacea) of Costa Rica with notes on some species

Sixteen species of Copepoda were recorded in this first detailed study of Costa Rican zooplankton. Two of these species are halophile. Notes are given on some of the species and their distribution. One new species found will be described elsewhere. The Costa Rican fauna resembles in composition the fauna of other Central American and Caribbean regions. Relatively few species were recorded. This is partly due to a low intensity of sampling but also to the paucity of lentic habitats. The occurrence of two circumtropical species of Mesocyclops is interesting.

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Résumé 16 espèces de Copépodes ont été inventoriées au cours d'une première étude détaillée du zooplankton dulcaquicole de Costa Rica. Deux des espèces trouvées sont halophiles. Des remarques sont faites a propos de quelques espèces et de leur répartition. Une nouvelle espèce est nouvelle — elle sera décrite par ailleurs. La fauna de Costa Rica ressemble par sa composition à celle des autres pays d'Amérique centrale et des îles caraibes. Relativement peu d'espèces sont notées. La faible intensité de l'échantillonnage mais aussi la pauvreté en habitats limniques en sont responsables. La présence de deux espèces circumtropicales de Mesocyclops est intéressante.

     

Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review

The studies on marine copepods of Costa Rica started in the 1990’s and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance of the inland copepod fauna of Costa Rica requires more detailed surveys.     

Historical biogeography of Iberobathynella (Crustacea, Syncarida, Bathynellacea), an aquatic subterranean genus of Parabathynellids, endemic to the Iberian Peninsula

• 1 The origin and distribution of the species of freshwater interstitial (stygobiont) syncarids of the Iberobathynella genus (Crustacea, Parabathynellidae), endemic to the Iberian Peninsula, are considered in the context of evolutionary biogeography.
• 2 We established the most likely phylogenetic relationships between the 14 known species of the Iberobathynella genus on the basis of morphological characters. We assumed a common marine ancestor and estimated the possible phylogenetic ages of the 14 inland species from the number of cladogram nodes.
• 3 The land ages at the sites where the species are found help to tell us when the landmasses emerged definitively: most species are found in areas that have undergone one or more marine transgressions/regressions since the Triassic and which could therefore have been colonized by the common ancestors.
• 4 We assessed the Boutin–Coineau two‐step model of colonization and evolution in an attempt to elucidate the evolutionary history of Iberobathynella and to offer a plausible palaeogeographical scenario. We looked for concordance between the possible chronology of Iberobathynella taxa colonization and their phylogenetic relationships, but found none of significance. Hence, we cannot reject the possibility that evolutionary clade divergence within the genus was independent of sea‐level changes in the Senonian (88.5–65 mya) and Eocene (56.5–35.4 mya) epochs. We can therefore neither confirm nor rule out a correlation.

     

On the ecology of marine cyclopoid copepods (Crustacea, Copepoda)

The goal of these studies was to improve our understanding ofhow Oithonidae and Oncaeidae can exist in nearly every partof the ocean. In particular, it was intended to obtain quantitativeinformation on reproduction rates and the longevity of adultfemales, and on feeding and growth rates of Oncaeidae. Whenfeeding at relatively high food levels, early copepodids ofOncaea mediterranea ingested     

Hadodiaptomus dumonti n. gen., n. sp., a new freshwater stygobitic calanoid (Crustacea: Copepoda: Calanoida) from Vietnam (South Asia) and a new member of the subfamily Speodiaptominae Borutzky, 1962

A new species of freshwater stygobitic calanoid, Hadodiaptomus dumonti n. gen., n. sp., from a cave in Vietnam (South Asia) is described. It is the ninth taxon from the order Calanoida described from freshwater subterranean (i.e. cave) environments. It is the fourth member of the subfamily Speodiaptominae Borutzky, 1962. It differs from stygobitic taxa in Europe and Mexico by numerous characters, especially in the armature of P1–P5, antenullas, mouth parts and genital segments in both sexes. Arthrodial membrane development from CII to CV is different from epigean as well as from subterranean taxa. These differences suffice to raise a new genus–Hadodiaptomus, characterised by two-segmented exopodites and endopodites of P1–P4 and reduced P5 endopodites in both sexes. Males are without widened segments 13–18 on right A1. Relations with other stygobitic taxa of the subfamily Speodiaptominae are discussed.     

Assessing the diversity of New Zealand freshwater harpacticoid copepods (Crustacea: Copepoda) using mitochondrial DNA (COI) barcodes

Taxonomic and ecological studies of freshwater harpacticoid copepods are limited globally by the ability to easily and accurately identify specimens. Here, we test the use of the mitochondrial cytochrome c oxidase subunit I (COI) gene locus as a tool for assessing the diversity of freshwater Harpacticoida. We obtained sequences from New Zealand harpacticoid copepods, representing two families, five genera and nine species, including the non-indigenous Elaphoidella sewelli. All species were delineated by the COI gene. However, high intraspecific diversity was evident among populations of Elaphoidella bidens (>12%), and between North and South Island populations of Bryocamptus pygmaeus (>18%), potentially indicating the presence of morphologically cryptic taxa. We suggest that mitochondrial DNA (COI) sequences can provide a useful tool for the routine identification of freshwater harpacticoid copepods. Applications of these data will include assessing species diversity and biogeography as well as assisting with the detection of non-indigenous species.     

A new genus and species of cyclopoid (Crustacea,Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico

A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13.     

Distribution patterns of freshwater Ostracoda (Crustacea) in the Canary Islands with regards to habitat use and biogeography

In this study biogeographic patterns and habitatrelationships of freshwater Ostracoda wereinvestigated in the Canary Island archipelago. Mostdata were collected from published studies, thoughalso new data from Gran Canaria are presented. In all,22 freshwater species are presently known to theCanaries. Six species, viz. Ilyocypris bradyi,Cypris bispinosa, C. pubera, Herpetocypris chevreuxi, Heterocyprisincongruens, and Sarscypridopsis lanzarotensisare new to Gran Canaria, the first two also being newto the Canaries in general. Testing the influence ofa number of variables on faunal richness indicatedonly a weak association with island area. Distancesbetween islands also proved not significant, and sodid other properties of islands, including age,altitude and precipitation. This was in contrast to acomparison set of data comprising aquatic beetles.Like beetles, however, ostracods did not show a nestedpattern, i.e. faunas of species-poor islands were notsubsets of species-rich island faunas. By having lowendemicity (endemic species lacking in the Canaries),the ostracod fauna resembled island fern floras. Bothgroups of organisms have tiny diaspores (diameter<0.1 mm) and are extensively parthenogeneticsuggesting similar dispersal and founder mechanisms.We identified a pattern (with one exception), wherethose species with distributions extending acrossseveral islands also had wider within-islanddistributions. Many species showed affinities todifferent habitats depending on conductivity of water,altitude and habitat types: whether they werepermanent or temporary, hypogean or epigean, orcharacterized by running or stagnant waters.     

Historical biogeography of some river basins in central Mexico evidenced by their goodeine freshwater fishes: a preliminary hypothesis using secondary Brooks parsimony analysis

Aims Our aim was to uncover and describe patterns of historical biogeography of the main river basins in central Mexico, based on a secondary Brooks parsimony analysis (BPA) of goodeine fishes, and to understand the processes that determine them with respect to the molecular clock of the goodeines and the geological events that have taken place in the region since the Miocene. Location The region covered in this study includes central Mexico, mostly the so‐called Mesa Central of Mexico, an area argued to be a transitional zone comprising several major river drainages from their headwaters at high elevations along the Transmexican Volcanic Belt to the coast of the Gulf of Mexico and the Pacific Ocean. Methods Based on a previous phylogenetic hypothesis regarding the Goodeidae, we built a data matrix using additive binary coding. First, we conducted a primary BPA to provide general explanations of the historical biogeography of Central Mexico. As ambiguity was found, a secondary BPA was conducted, and some areas were duplicated in order to explain the reticulated history of the area. Area cladograms were obtained by running a parsimony analysis. Instances of vicariance and non‐vicariance processes were described with reference to the cladogram obtained from secondary BPA. Results The study area was divided into 18 discrete regions. Primary BPA produced nine equally parsimonious cladograms with 129 steps, and a consistency index (CI) of 0.574. A strict consensus cladogram shows low resolution among some areas, but other area relationships are consistent. For secondary BPA, five of the 18 regions were duplicated (LEA, COT, AYU, CUT, PAN); one was triplicated (BAL); and one was quadruplicated (AME), suggesting that the pattern of distribution of species in these areas reflects multiple independent events. These areas correspond with the regions exhibiting the highest levels of diversification and the most complex geological history, and those for which river piracy events or basin connections have been proposed. The secondary BPA produced a single most parsimonious cladogram with 118 steps, and a CI of 0.858. This cladogram shows that none of the duplicated areas are nested together, reinforcing the idea of a reticulated history of the areas and not a single vicariant event. Main conclusions Although our results are preliminary and we cannot establish this as a general pattern, as the BPA is based on a single‐taxon cladogram, resolution obtained in the secondary BPA provides some insights regarding the historical biogeography of this group of fishes in river basins of central Mexico. Secondary BPA indicates that the historical biogeography of central Mexico, as shown by their goodeine freshwater fishes, is complex and is a result of a series of vicariant and non‐vicariant events such as post‐dispersal speciation and post‐speciation dispersal.