Caribbean Species Research Articles

NEW SPECIES OF OSWALDOCRUZIA (NEMATODA: MOLINEIDAE) IN AMEIVA FESTIVA (SQUAMATA: TEIIDAE) FROM NICARAGUA

Oswaldocruzia nicaraguensis n. sp. (Strongylida: Molineidae) from the intestines of Ameiva festiva (Sauria: Teiidae) is described and illustrated. Oswaldocruzia nicaraguensis represents the 78th species assigned to the genus and is most similar to the Caribbean species of the genus by possessing spicules in which each of the 3 divisions terminates in numerous fine points. Of the 8 species assigned to this group, O. nicaraguensis is most similar to Oswaldocruzia moraveci; of the 8 species, only O. moraveci and O. nicaraguensis possess a type II bursa and lack cervical alae. It is separated from O. moraveci by the position of the tips of ribs 5-6; close together in O. nicaraguensis, well separated in O. moraveci.

NEOGENE CUPULADRIIDAE OF TROPICAL AMERICA. I: TAXONOMY OF RECENT CUPULADRIA FROM OPPOSITE SIDES OF THE ISTHMUS OF PANAMA

We used up to 28 morphological characters to discriminate and describe species of the genus Cupuladria based on entire colony specimens collected from both coasts of the Isthmus of Panama. The characters included a combination of zooidal features traditionally used in cheilostome taxonomy and nontraditional characters such as colony size, shape, and an index of calcification of the colony, as well as the size of the basal sectors and their number of pores. Species were discriminated by a series of repeated multivariate cluster and discriminant analyses until the majority of specimens were assigned to their putative species with high statistical confidence. Nontraditional characters contributed significantly to the power of the analyses. Colonies fell into two highly distinct groups most clearly recognized by the presence or absence of vicarious avicularia, which agrees well with previous molecular genetic analyses. Further analyses of each of these two groups considered separately resulted in the discrimination of eight species. These include two previously described Caribbean species, C. biporosa Canu and Bassler, 1919 and C. surinamensis Cadée, 1975, and six new species: C. multesima, C. incognita, C. cheethami, and C. panamensis from the Caribbean, and C. pacificiensis and C. exfragminis from the eastern Pacific. There was also good correspondence between major clades within these morphologically defined groups and the previous molecular analysis, although 20% of the specimens could not be distinguished from their cognate (“geminate”) species from the opposite ocean. The high ratio of undescribed to described species and higher diversity in the Caribbean than eastern Pacific agree well with newly described patterns from other cheilostome genera based on similar analyses. Quantitative morphometric studies are essential to study biologically meaningful patterns of cheilostome speciation and macroevolution in the fossil record.

Crassitegula walsinghamii (Sebdeniaceae, Halymeniales), a new red algal genus and species from Bermuda based upon morphology and SSU rDNA sequence analyses

Dorsiventral, mat-forming plants superficially similar to Flahaultia tegetiformans (Gigartinales, Solieriaceae), a Caribbean species known only in the vegetative condition, were collected in several Bermuda habitats. Morphological analysis of these specimens distinguished them from F. tegetiformans. Reproductive morphology and analyses of sequences of the nuclear encoded small subunit rDNA show them clustering with Sebdenia (Halymeniales). The plants are described as Crassitegula walsinghamii gen. et sp. nov., a new nemathecial member of the Sebdeniaceae.

Geographic and stratigraphic distributions of the Caribbean species of Cladocora (Scleractinia, Faviidae)

A complete account of the faviid genus Cladocora within the Caribbean is presented. In the Caribbean this genus represents an extant group that had its earliest occurrence during the Campanian-Maastrichtian of Jamaica. Recent forms have been reported throughout the Caribbean. The following forms were found (with stratigraphic ranges in the Caribbean): C. arbuscula (Pliocene-Recent), C. debilis (Pleistocene-Recent), C. gracilis (Middle-Upper Maastrichtian), C. jamaicaensis (Campanian-Maastrichtian and Eocene), C. johnsoni (Pliocene), and C. recrescens (Middle-Upper Oligocene). The occurrence of the genus Cladocora in the Caribbean is largely continuous from the Campanian to Recent, during the majority of the Caribbean species show affinities to European assemblages. For the time intervals Paleocene, Lower Oligocene, and Miocene the taxon has not been reported from the Caribbean.

The effect of territorial damselfish (family Pomacentridae) on the space use and behaviour of the coral reef fish, Halichoeres bivittatus (Bloch, 1791) (family Labridae)

Most demersal species of damselfish (family Pomacentridae) are territorial herbivores that aggressively chase other fishes away from their nests. This study investigates whether the aggressive territorial damselfish, Stegastes leucostictus, modifies behaviours and home range area use in a less aggressive, non-territorial species, the slippery dick wrasse, Halichoeres bivittatus (family Labridae). Damselfishes and wrasses are ubiquitous and abundant members of coral reef fish assemblages around the world; hence, this study has broader implications beyond the two Caribbean species chosen for this study. A manipulative field experiment consisted of transplanting one or three S. leucostictus into artificial shelters positioned within adult or adjacent to juvenile H. bivittatus home ranges. The introduction of damselfish had little effect on the size of home range areas of juvenile or adult wrasses, but had a significant effect on the location of their home ranges. The damselfish also affected adult microhabitat use but did not affect use by juveniles. In addition, there was an increase in damselfish–wrasse interactions that resulted in a significant reduction in the amount of time adult wrasses could spend foraging or in a foraging assemblage. It was concluded that aggressive interactions with territorial damselfish affect individual H. bivittatus space use and may consequently affect the spatial distribution of H. bivittatus populations.

Eudendrium klausi (Cnidaria, Hydrozoa), a new species of hydroid from Belize

A new species of the cosmopolitan genus Eudendrium, E. klausi, is described from Carrie Bow Cay, Belize. The species is characterized by a small colony with an intense blue colour, polyps armoured with large microbasic euryteles scattered on the hydranth body, hypostome, and female spadix; female gonophores on normal hydranths with a reduced number of tentacles. The new species is compared to other Eudendrium with similar cnidome, and other Caribbean species, including those described by Allman (1877). Among the latter, E. gracile, E. laxum, E. attenuatum, and E. tenellum (sensu Allman) are considered as species inquirenda due to the lack or the unsuitability of the type materials and the inconclusive original descriptions. Eudendrium exiguum, E. eximium, and E. fruticosum were also studied and demonstrated to be different from E. klausi sp. nov.

Current trends of space occupation by encrusting excavating sponges on Colombian coral reefs

AbstractSome sponges of the genus Cliona (Porifera, Hadromerida, Clionidae) simultaneously excavate and encrust calcareous substratum, competing aggressively for illuminated space with corals and other organisms. To interpret current trends of reef space occupation, the patterns of distribution and size of three Caribbean species were examined at San Andrés Island and Islas del Rosario in Colombia. While Cliona aprica was ubiquitous, C. caribbaea (= C. langae) preferred deep and protected reef zones, and C. tenuis shallow and wave‐exposed settings. In contrast to the effect on other excavating sponges, chronic exposure to raw sewage did not significantly increase the abundance of the studied sponges. Substratum occupation/availability ratios showed a positive tendency of the sponges toward certain coral skeletons, and a negative or neutral tendency toward calcareous rock, indicating that establishment may be easier on clean, recently dead coral than on older, heavily incrusted substratum. High relief generally limits sponge size to that of the illuminated portions of the substratum. A generally lower proportion of small individuals than of larger ones indicates currently low recruitment rates and low subsequent mortality. Successful events of higher recruitment seem to have occurred for C. tenuis. These are related to the massive acroporid coral die‐off in the early 1980s and to asexual dispersion during storms, resulting in a current 10% substratum cover. Reefs with high coral mortality were and/or are thus more susceptible to colonization and subsequent space occupation by these sponges, although relief may prevent space monopolization.

Mendelian microsatellite loci for the Caribbean coral Acropora palmata

The genus Acropora constitutes the most species-rich clade of hermatypic corals, and its members are important reef builders throughout their broad tropical range. In the Caribbean, acrop- orid populations have declined over the last 2 decades due to disease, hurricanes, predation, and bleaching episodes, and some are now subjects of conservation efforts. Genetic estimates of popula- tion connectivity and clonal structure should be part of these efforts, but such studies have been ham- pered by low levels of mitochondrial DNA variation in corals, and an apparent dearth of variable sin- gle-copy nuclear markers. Developing microsatellite markers in Acropora has proven especially difficult. We used Southern blotting to reveal that, indeed, some microsatellite motifs (AAC, AAG) are rare in the genome of the Caribbean species Acropora palmata. However, repeats with the motif AAT are both abundant and variable. We developed 8 polymorphic microsatellite markers for A. palmata, and performed crosses to confirm co-dominant inheritance patterns. Five of the 8 mark- ers tested show simple Mendelian inheritance (mean observed heterozygosity = 0.84, mean number of alleles per locus = 8.6). Along with outcrossed sexual larvae, individual egg donors also produced some triploid and selfed larvae that developed normally and survived for 80 h, when the experiment was terminated. The markers reveal variation among 3 Florida populations of A. palmata and among clones within 1 of these populations. Seven of the markers amplify DNA from A. cervicornis and 8f rom the hybrid A. prolifera. These markers should prove to be valuable tools for developing conservation strategies for Caribbean acroporid species.

PLACING THE FLORIDIAN MARINE GENETIC DISJUNCTION INTO A REGIONAL EVOLUTIONARY CONTEXT USING THE SCORCHED MUSSEL, BRACHIDONTES EXUSTUS, SPECIES COMPLEX

The well-documented Floridian Gulf/Atlantic marine genetic disjunction provides an influential example of presumed vicariant cladogenesis along a continental coastline for major elements of a diverse nearshore fauna. However, it is unclear if this disjunction represents a local anomaly for regionally distributed morphospecies, or if it is merely one of many such cryptic phylogenetic splits that underlay their assumed genetic cohesiveness. We aimed to place the previously characterized scorched mussel Gulf/Atlantic genetic disjunction into a regional phylogenetic perspective by incorporating genotypes of nominal conspecifics sampled throughout the Caribbean Basin as well as those of eastern Pacific potential geminate species. Our results show it to be one of multiple latent regional genetic disjunctions, involving five cryptic Caribbean species, that appear to be the product of a long history of regional cladogenesis. Disjunctions involving three stem lineages clearly predate formation of the Isthmus of Panama and of the Caribbean Sea, although four of the five cryptic species have within-basin sister relationships. Surprisingly, the Atlantic clade was also found to be widespread in the southern Caribbean, and ancestral demography calculations through time for Atlantic coast-specific genotypes are consistent with a northward range extension after the last glacial maximum. Our new data seriously undermine the hypothesis of a Floridian vicariant genesis and imply that the scorched mussel Gulf/Atlantic disjunction represents a case of geographic and temporal pseudocongruence. All five Caribbean Basin cryptic species exhibited an intriguing pattern of predominantly allopatric distribution characterized by distinct geographic areas of ecological dominance, often adjoining those of sister taxa. This pattern of distribution is consistent with allopatric speciation origins, coupled with restricted postspeciation range extensions. Several lines of indirect evidence favor the hypothesis that the predominantly allopatric distributions are maintained over evolutionary time scales, primarily by postrecruitment ecological filters rather than by oceanographic barriers to larval-mediated gene flow.

Reproductive strategies in gastropods across the Panama seaway

Summary Biogeographic patterns of marine organisms can be related to historical or ecological factors. In either case, an organism's dispersal capabilities may have an impact on rates of speciation, extinction, and species longevity. One way to assess these factors is to compare patterns and trends in developmental modes among closely related taxa across different environments. The Caribbean and the eastern Pacific differ greatly in primary productivity and seasonality. The latter is more seasonal and productive, and these differences have existed for several million years. Likewise, reproductive propagules (eggs, larvae) of echinoderms, corals, and bryozoans are smaller or mostly planktonic in the eastern Pacific when compared with the Caribbean. This is probably due to the greater seasonality and higher productivity of the eastern Pacific, as opposed to the more stable, less productive Caribbean. This study used protoconch morphology to infer developmental patterns for 84 recent species of columbellid gastropods of the Strombina group, Conus, Oliva, and Olivella. Planktotrophy predominates within the eastern Pacific, whereas Caribbean species show mostly non-planktotrophic development. Thus mollusks exhibit the same differences between these two oceans as the other phyla. Most studies of evolutionary trends in modes of development have been done for north Atlantic and Mediterranean species. There, non-planktotrophic development increases with latitude and bathymetry. However, our data from the Eastern Pacific indicates that the widely reported tendency to evolve from planktotrophic to direct development may reflect changing environmental conditions in the Atlantic rather than an inevitable evolutionary trend. These results agree with a few studies for the south Atlantic and Antarctic regions that indicate that latitudinal and bathymetric constraints on developmental modes are probably much more complex than initially assumed. Moreover, the effects imposed by phylogeny on life histories can either direct or constrain the observed shifts in developmental types.

Transportation techniques for massive scleractinian corals

AbstractTransportation techniques for scleractinian corals have been described mainly for fragments and small colonies. As part of a recent study on captive sexual reproduction of the Caribbean species Montastrea annularis and Diploria strigosa, we transported relatively large (max. diameter of 21 cm), heavy (max. weight of 9,200 g) colonies of both species from Curaçao, Netherlands Antilles, to Rotterdam, The Netherlands. A new transportation technology was applied whereby the corals were transplanted to specially designed PVC crosses to provide stabilization during transport. In two transports (November 2001 and February 2002), 100 colonies were transported submerged, in a shipping time of >35 hr. The survival rate measured 2 weeks after transport was 100%. Four and 8 months after transport, respectively, two colonies of D. strigosa died without any obvious cause. In November 2002 we observed an outbreak of Dark Spots disease (DSD) affecting two‐thirds of the colonies of M. annularis. Although the colonies did not show any symptoms when they were collected, the disease most probably was transferred when the coral were transported from the field to the laboratory. The presented method is appropriate for transporting large, heavy corals–especially for scientific purposes. In general, species‐specific properties, colony size, and transportation time determine which transportation method should be applied. In the future, there may be a shift toward transports of fragments, coral larvae, and primary polyps to reduce collections in the field. Zoo Biol 23:165–176, 2004. © 2004 Wiley‐Liss, Inc.

Life history variation in cupuladriid bryozoans from either side of the Isthmus of Panama

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 280:145-161 (2004) - doi:10.3354/meps280145 Life history variation in cupuladriid bryozoans from either side of the Isthmus of Panama Aaron O¹Dea1,2,*, Amalia Herrera-Cubilla1, Helena Fortunato1, Jeremy B. C. Jackson1,2 1Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, Box 2072, Balboa, Ancon, Republic of Panama 2Geosciences Research Division, Scripps Institution of Oceanography University of California, San Diego La Jolla, California 92093-0244, USA *Email: odeaa@si.edu ABSTRACT: Cupuladriid bryozoans are able to produce new colonies both sexually through the production of larvae and asexually via fragmentation. The prevalence of asexual propagation and the physical and biological processes of fragmentation in cupuladriid species are currently little understood. In a large survey comprising collections of nearly 32000 cupuladriids from either side of the Isthmus of Panama, patterns of cupuladriid species richness, occurrence and abundance were measured together with levels of asexual propagation, fragmentation and regeneration. The Caribbean side is characterised by greater cupuladriid diversity and dominance of the genus Cupuladria over Discoporella while the eastern Pacific coast is characterised by lower cupuladriid diversity and complete dominance of Discoporella. Life history variation was not found to be constrained by phylogeny and no systematic differences were found in life history or morphologies between Cupuladria and Discoporella to explain the patterns in generic dominance across the isthmus. Nonetheless, striking differences occur in life history strategies across the isthmus. Eastern Pacific species tend to be large, flat and lightly calcified, resulting in high levels of fragmentation and hence asexual propagation. Conversely, Caribbean species produce a wider range of morphologies, including small, highly domed and highly calcified colonies that protect from fragmentation. By correlating colony morphologies with reproductive life histories within species, we show that morphologies, particularly colony strength and size, control levels of fragmentation and thus mode of propagation in cupuladriids. Life history strategies that promote asexual propagation are found to track levels of primary productivity both between oceans across the isthmus and between regions within oceans. KEY WORDS: Asexual · Sexual · Life history · Cupuladriid · Bryozoa · Reproduction · Panama Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 280. Online publication date: October 14, 2004 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2004 Inter-Research.

Sexual Morphology, Reproduction and the Evolution of Bioluminescence in Ostracoda

A broad array of the highly variable morphological characters available in Ostracoda were used (1) to construct a new tabular key to the families of the subclass Myodocopa (and to differentiate the Myodocopa from the Podocopa), and (2) to explore the evolution of bioluminescence in the myodocopid family Cypridinidae. Results of a cladistic analysis of the Cypridinidae strongly support a single origin of bioluminescence within the family; a single clade contains at least 64 species known to luminesce (not all described). Furthermore, within that large clade, complex bioluminescent mating displays were confined by the analysis to a single clade of exclusively Caribbean cypridinids, though that result was unresolved by bootstrap analysis.Chemically different bioluminescence occurs convergently in two ostracode groups; it is produced within carapace glands of certain Halocypridina, but it is produced and extruded from the upper lips of many cypridinid Myodocopida and serves as an antipredatory behavior in both groups. Additionally at least 60 cypridinid species also produce spectacular and complex species-specific male mating displays nightly in the Caribbean Sea. The cladistic analysis using 58 morphological characters of 44 taxonomic units (24 described genera of Cypridinidae, 11 individual species assigned to the genus Vargula, six groups of bioluminescent signalling Caribbean species (many undescribed), the Cylindroleberididae, and the Philomedidae) was performed using PAUP with the parsimony criterion. Twenty-five of the characters were previously underutilized characters of the complex upper lip and large male copulatory limbs discovered through dissection and SEM. These proved especially valuable, but characters of all other limbs were also included.The Cypridinidae was confirmed as a monophyletic taxon with several well-supported subclades in addition to the large bioluminescent one. Skogsbergia, which apparently uses an antennular fan of iridescent blue filaments in courtship (Parker, 1997) belongs to a clade with five other cypridinid genera, including the four that have a similar fan. The genus Vargula was determined to be a polyphyletic assemblage. New genera will be established for former Vargula species including: “V.” tubulata, “V.” hilgendorfii, “V.” tsujii and all bioluminescent signaling species. Similar problems may exist for other large cypridinid genera, and clearer resolution of generic definitions might possibly reveal more significant patterns of geographic distribution within the family.Most characters of the carapace were found to be too convergent to be useful. Though carapace characters are diagnostic for some ostracode taxa, most should not be used by themselves to identify ostracodes with certainty. General aspects of reproduction are also reviewed.

Critical comments on the South Atlantic puzzle of reef fish biogeography [J.‐C. Joyeux, S.R. Floeter, C.E.L. Ferreira & J.L. Gasparini (2001) Biogeography of tropical reef fishes: the South Atlantic puzzle. Journal of Biogeography, 28, 831–841

Critical comments on the South Atlantic puzzle of reef fish biogeography [J.‐C. Joyeux, S.R. Floeter, C.E.L. Ferreira &amp; J.L. Gasparini (2001) Biogeography of tropical reef fishes: the South Atlantic puzzle. <i>Journal of Biogeography</i>, 28, 831–841

Phylogenetic relationships within the coral crab genus Carpilius (Brachyura, Xanthoidea, Carpiliidae) and of the Carpiliidae to other xanthoid crab families based on molecular sequence data

The coral crab genus Carpilius currently includes three widely distributed species that inhabit tropical coral reefs and adjacent waters. The relationship of Carpilius to other xanthoid crabs is unknown. Previously, carcinologists considered Carpilius to be allied with crabs of the family Xanthidae (e.g., Euryozius, Liagore, and Liomera), however, recent workers have considered it to be a monotypic genus within its own family, Carpiliidae. Mitochondrial 12S- and 16S-rDNA gene fragments confirm the monophyly and distinct status of the family Carpiliidae. Within the genus Carpilius, the Caribbean species C. corallinus is basal to the two Pacific species C. maculatus and C. convexus. The Pacific species are sister taxa, despite the greater morphological resemblance of C. corallinus to the Pacific C. convexus. The relationship of the Carpiliidae ( Carpilius) to other xanthoid crabs is investigated, and results of a preliminary analysis of higher xanthoid relationships did not resolve the relationships of Carpiliidae, “Xanthidae,” Menippidae, Trapeziidae, and Ocypodidae to one another. A Menippidae and Carpilius relationship could not be rejected, although a Liomera, Liagore, and Carpilius relationship was.

Molecular phylogeny and phylogeography of free-living Bryozoa (Cupuladriidae) from both sides of the Isthmus of Panama

Genetic data were used to identify Recent species of free-living bryozoans (Cupuladriidae) from both sides of the Isthmus of Panama, and to examine their phylogenetic relationships, species richness, and population structures. An approximately 480 bp fragment of the 16S mitochondrial rRNA gene was sequenced from 182 individuals from Panama, the Gulf of Mexico, and El Salvador. Ten haplotype groups ( Cupuladria 4, 5, and 6; Discoporella 1, 2, 3A, 3B, 3C, 7, and 8) were identified. Genetic distances between haplotype groups (3.2–26.5%; K2P + Γ) were 1–2 orders of magnitude greater than within groups (0.1–1.4%). Seven of the haplotype groups represent morphologically distinct species; Discoporellas 3A–C appear to be cryptic species. Phylogenetic analyses identified two pairs of transisthmian sister clades. An average divergence rate derived from other taxa suggests that Cupuladrias 4 and 5 diverged ≈7 Ma, a Discoporella 7 clade diverged from a 3A–C clade ≈11 Ma, and the 3A–C clade radiated ≈6–4 Ma; these events all predated final closure of the isthmus? 3 Ma. The Caribbean side of the isthmus, with 5 species, is only marginally richer in cupuladriids than the Pacific side, with 4, but has greater phylogenetic depth. The Caribbean retains lineages stemming from a New World Miocene radiation that are not represented in the eastern Pacific; extant eastern Pacific cupuladriids share most recent common ancestry with only two of the Caribbean lineages. Species in the eastern Pacific tend to show shallow population structures, with high levels of gene flow between geographically separate populations, whereas Caribbean species tend to show deeper populations structures, with indications of restricted gene flow between Bocas del Toro/Gulf of Mosquitos and Costa Arriba/San Blas. The population structures derive from Pleistocene histories and may be of limited value in interpreting the macroevolutionary pattern, as our results provide no evidence of speciation on either side of the isthmus following closure in the late Pliocene.

Green‐fluorescent proteins in Caribbean corals

Fluorescent pigments in several Indo‐Pacific and Caribbean anthozoans have recently been identified as proteins related to the Green‐fluorescent protein (GFP) of the hydromedusa Aequorea victoria. Here we show that GFP is widely distributed in many Caribbean species. The fluorescence excitation and emission spectra for the pigment are similar to those reported elsewhere for coral and noncoral GFP and the fluorescence quantum yield is estimated to be 35%. Spectral and molecular characterization of the isolated protein clearly show it to be GFP, and laboratory and in situ fluorescence measurements and Western blot analysis show that it is widespread. Bathymetric studies of GFP content using Western blots for the ecologically important congeneric corals Montastraea faveolata and Montastraea cavernosa show that there is no significant correlation between depth and GFP concentration. Nucleotide sequence data of GFP from M. faveolata and M. cavernosa show 88.2% sequence homology with each other and 46.4% homology with A. victoria GFP, whereas the percent homology with A. victoria at the amino acid level was 31.1 and 28.4% for M. cavernosa and M. faveolata, respectively, and 82.7% with each other. Measurements of reflectance and of the excitation spectrum for chlorophyll fluorescence in GFP‐containing corals indicate that GFP absorption, emission, and reflection have negligible impact on the level of solar radiation reaching the zooxanthellae and therefore play no role in coral photosynthesis by either addition or removal of photons.

Origin and phylogenetic position of the Lesser Antillean species of Bothrops (Serpentes, Viperidae): biogeographical and medical implications

We use mitochondrial DNA sequences to infer the origin and phylogenetic position of the Lesser Antillean species of the pitviper genus Bothrops, B. caribbaeus and B. lanceolatus. The two species form a monophyletic group, which in turn forms the sister clade to the Bothrops asper-atrox complex. High levels of sequence divergence among the Caribbean species, and between them and the nearest mainland relatives, suggest a relatively ancient origin of these snakes. The hypothesis that the Lesser Antillean Bothrops are the result of a recent colonisation event from within the South American B. atrox complex is rejected, as is the hypothesis that they were introduced to their island habitats by aboriginal humans. The high level of morphological apomorphy displayed by B. lanceolatus suggests a stepping-stone colonisation, St. Lucia being colonised first and then Martinique from St. Lucia. The medical implications of these findings are discussed: a recent case of envenoming from Saint Lucia suggests that Bothrops caribbaeus causes the same thrombotic syndrome of envenoming as B. lanceolatus.

Genetic divergence within the Drosophila mayaguana subcluster, a closely related triad of Caribbean species in the repleta species group

The mayaguana triad of the Drosophila repleta species group includes D. mayaguana, D. straubae, and D. parisiena, the latter two of which are very similar when examined morphologically. Many morphological characters used to define these taxa are quantitative and overlap substantially among some forms--it is only through suites of such characters that species can be identified. We apply Population Aggregation Analysis and tree building methods to five rapidly evolving gene regions--the mitochondrial AT rich region and the nuclear acetylcholinesterase, hunchback, mastermind, and vestigial loci to test the morphological species delineations within the morphocryptic mayaguana triad. We find that D. mayaguana is diagnosable using DNA sequences, but the other two species form a non-diagnosable paraphyletic assemblage. A single ecological factor, oviposition substrate, is an important diagnostic character distinguishing D. straubae from D. parisiena, highlighting the importance of examining a diverse array of data (morphological, molecular, ecological, and behavioral) when defining species limits.

Genetic divergence within the Drosophila mayaguana subcluster, a closely related triad of Caribbean species in the repleta species group

Genetic divergence within the Drosophila mayaguana subcluster, a closely related triad of Caribbean species in the repleta species group