Caribbean Species Research Articles

Morphological recognition of cryptic species in the planktonic foraminifer Orbulina universa

One of the key hypotheses of paleoceanography is that planktonic foraminiferal morphospecies record reasonably stable and homogeneous oceanographic and climatic characteristics over their geographic and stratigraphic ranges. The discovery of numerous genetically-defined cryptic species challenges the morphospecies concept in planktonic foraminifera and paleoceanographic interpretations based on them. Here, we present a combined genetic and biometric analysis of Orbulina universa specimens in the Atlantic, Indian and Pacific Oceans. Our study is based on shells retained after DNA extractions. On those genotyped shells, we perform biometric analyses (shell size and thickness, inner porosity and pore surface distribution). Our genetic data confirm the presence of three cryptic species of O. universa in the world ocean, whose distributions are primarily correlated to the productivity of the surface waters. The Mediterranean species of O. universa is most abundant in the vertically mixed and nutrient-rich areas of the low to mid-latitudes, whereas the Caribbean and Sargasso species occur in stratified and oligotrophic subtropical waters. Our biometric data show no correlation between shell size and inner porosity within each cryptic species of O. universa. Combining Principal Component Analyses with MANOVAs performed on shell pore surface distribution, we demonstrate that the three different cryptic species are characterized by significant morphological differentiation. The Caribbean species typically exhibits large pores and higher porosity values, while the Mediterranean and Sargasso species are characterized by smaller pore areas and shell porosity. A model based upon pore surface distribution correctly assigns 60% to 90% of the specimens to their corresponding genotype. Although the inner shell surface of the Sargasso species resembles that of the Mediterranean species, our model demonstrates that the pore surface distributions of these two cryptic species can be distinguished. Finally, the Sargasso species exhibits significantly thinner shells than the two other cryptic species.

Organization of a dispersed repeated DNA element in the Zamia genome

Occurrence and genomic organization of dispersed elements containing ZpS1 satellite repeats have been investigated in a wide representation of species of the old plant genus Zamia (Zamiaceae, Cycadales). In Z. paucijuga, the ZpS1 repeat is organized as long satellite DNA arrays and as short arrays inserted into AT-rich dispersed elements. A comparative study by Southern analysis shows that these unusual dispersed elements containing the ZpS1 repeat are present with different organizations in all investigated Zamia species. In some species these elements are present with a low copy number, while in other species secondary amplification events, involving specific sequence clusters, appear to have generated characteristic dispersed elements in a high copy number. Among Zamia species, several groups share similar restriction patterns, as the Zamia loddigesii complex and the Caribbean species suggesting a general correlation between organization and genomic representation of the dispersed repeated sequence and the pattern of phyletic relationships in the genus. However, the finding of different patterns also among closely related species suggests a complex history of amplifications and losses of these dispersed repetitive elements that cannot be always easily traced through the phylogenetic reconstruction of this ancient plant group.

Taxonomic Revision of the Vachellia acuifera Species Group (Fabaceae: Mimosoideae) in the Carribean

Twelve Caribbean species of Vachellia (formerlyAcacia subgenus Acacia) are formally monographed with taxonomic, habitat, geographic distribution descriptions, and lists of representative specimens examined. The species treated here are all part of the informal Vachellia acuifera group, which is characterized by generally enlarged stipular spines borne in clusters on the stems, 1–3 pairs of pinnae per leaf, and 20–50 stamens. Ordination analyses of vegetative characters show that these species form discrete groups in two- and three-dimensional plots. Vachellia baessleria Clarke, Seigler, & Ebinger, endemic to Guantánamo and Las Tunas, Cuba, is newly described. Vachellia acuifera is wide ranging, occurring from the Bahamas to Cuba. The other species are highly restricted in their distribution and ecological setting. Four of the species are only known from Hispaniola (V. barahonensis, V. caurina, V. cucuyo, and V. oviedoensis) and six only from Cuba (V. baessleria, V. belairioides, V. bucheri, V. daemon, V. roigii, and V. zapatensis). Another species, V. anagadensis, is only found on the island of Anegada in the British Virgin Islands.

FIRST RECORD OF THE INDO‐PACIFIC REEF CORAL GENUS ISOPORA IN THE CARIBBEAN REGION: TWO NEW SPECIES FROM THE NEOGENE OF CURAÇAO, NETHERLANDS ANTILLES

Abstract: The coral genus Isopora, a sister group of the modern dominant Acropora until now only known from the Pliocene to Recent of the Indo‐Pacific, is recorded in the Caribbean for the first time. Two new species, Isopora ginsburgi and Isopora curacaoensis, are described from the Neogene Seroe Domi Formation of Curaçao, Netherlands Antilles. Study of large collections made systematically through the sequence indicates that Isopora first occurred in the Caribbean during the Mio–Pliocene, at approximately the same time as the origination of many modern Caribbean reef coral dominants including Acropora cervicornis. It last occurred in the region during the late Pliocene as part of a pulse of extinction, in which several genera that live today in the Indo‐Pacific became extinct in the Caribbean. Throughout its Caribbean duration, Isopora co‐occurred with the two abundant modern Caribbean species of Acropora, A. cervicornis and A. palmata. Comparisons with Neogene collections made elsewhere in the Caribbean indicate that Isopora was restricted in distribution to the southern Caribbean. Isopora species are viviparous, while Acropora are oviparous, and this difference in reproductive strategy may have played a role in the extinction of Isopora in the Caribbean. The occurrences of Isopora reported in this study are the oldest records to date of Isopora worldwide, and are important for understanding the biogeographic separation between reef coral faunas in the Caribbean and Indo‐Pacific regions.

Life history of the spider Selenops occultus Mello‐Leitão (Araneae, Selenopidae) from Brazil with notes on the natural history of the genus

Selenopids are extremely fast‐moving, dorsoventrally flattened spiders and are among the most secretive of animals. However, they can be locally abundant, providing an opportunity to examine their life and natural histories. Here we report life history data from Selenops occultus which were studied and collected monthly for over a year at an experimental farm of São Paulo State University in Botucatu, Brazil. We compare these data with what we have found in other Selenops species in the Caribbean region. Overall, S. occultus showed considerable seasonality. Males were most common in January and March, whereas females were more common in June and November. Significant differences between the numbers of males collected during the wet and dry seasons indicate that mating may be limited to the wet season. The Caribbean species share similar natural histories to S. occultus, such as little conflict in small areas and overlapping generations throughout the year.

Molecular Microbial Diversity Survey of Sponge Reproductive Stages and Mechanistic Insights into Vertical Transmission of Microbial Symbionts

Many marine sponges, hereafter termed high-microbial-abundance (HMA) sponges, harbor large and complex microbial consortia, including bacteria and archaea, within their mesohyl matrices. To investigate vertical microbial transmission as a strategy to maintain these complex associations, an extensive phylogenetic analysis was carried out with the 16S rRNA gene sequences of reproductive (n = 136) and adult (n = 88) material from five different Caribbean species, as well as all published 16S rRNA gene sequences from sponge offspring (n = 116). The overall microbial diversity, including members of at least 13 bacterial phyla and one archaeal phylum, in sponge reproductive stages is high. In total, 28 vertical-transmission clusters, defined as clusters of phylotypes that are found both in adult sponges and their offspring, were identified. They are distributed among at least 10 bacterial phyla and one archaeal phylum, demonstrating that the complex adult microbial community is collectively transmitted through reproductive stages. Indications of host-species specificity and cospeciation were not observed. Mechanistic insights were provided using a combined electron microscopy and fluorescence in situ hybridization analysis, and an indirect mechanism of vertical transmission via nurse cells is proposed for the oviparous sponge Ectyoplasia ferox. Based on these phylogenetic and mechanistic results, we suggest the following symbiont transmission model: entire microbial consortia are vertically transmitted in sponges. While vertical transmission is clearly present, additional environmental transfer between adult individuals of the same and even different species might obscure possible signals of cospeciation. We propose that associations of HMA sponges with highly sponge-specific microbial communities are maintained by this combination of vertical and horizontal symbiont transmission.

EVOLUTIONARY RESPONSES TO ENVIRONMENTAL HETEROGENEITY IN CENTRAL AMERICAN ECHINOID LARVAE: PLASTIC VERSUS CONSTANT PHENOTYPES

Do changes in food resources lead to evolutionary changes in phenotypic plasticity or in different constant phenotypes? I addressed this question by studying plasticity of larval feeding arms for "geminate species pairs" in three echinoid genera. These closely related species were geographically isolated when the Panamanian Isthmus raised 2.8-3.1 million years ago, creating two different food level environments: high but variable food levels in the eastern Pacific versus chronically low food levels in the western Caribbean. I reared larvae of geminate species in different replicated food environments for 10 days postfertilization, collected morphological measurements of individual arm and body lengths, and calculated degrees of plasticity of relative arm length for each species. In contrast to previous studies with temperate echinoids, there was no significant plasticity of arm length in either the Pacific or Caribbean species considered here. Caribbean species, however, had significantly longer relative arm lengths than Pacific species, regardless of food levels. These results suggest that historical changes in food levels have led to the evolution of constant rather than plastic differences between Pacific and Caribbean echinoids. The evolution of plasticity may be limited by the timing of reproduction or by egg size in this system.

Multiple Events of Dispersal and Radiation of the Tribe Miconieae (Melastomataceae) in the Caribbean

In the Caribbean region, the Melastomataceae are represented by about 450 species (from 28 genera), close to 400 of them endemic. The majority of these endemic species (approximately 330) belong to the tribe Miconieae, a monophyletic group characterized by flowers with inferior or partly inferior ovaries that develop into baccate fruits, stamens with no or only poorly developed connective appendages, and the absence of megastyloids and imbricate bracts at the base of the flowers. A phylogenetic analysis of 460 accessions from 450 species of the tribe Miconieae, including 139 present in the Antilles (103 of these endemic), was performed based on nuclear (nrITS) and plastid (ndhF) DNA sequence data. This analysis shows that most of the Caribbean endemics are the product of five radiation events: (1) a clade containing the Caribbean endemic (or near-endemic) genera Pachyanthus, Calycogonium, Tetrazygia and Charianthus, as well as a few representatives of Miconia and Leandra. (2) The genus Mecranium. (3) The Caribbean species of Miconia section Chaenopleura (which are probably not the sister group of Andean Chaenopleura). (4) The Greater Antillean species of Clidemia and Ossaea (including Sagraea). (5) The Lesser Antillean representatives of Clidemia. Caribbean endemics that are more closely related to mainland species, rather than other Caribbean species are rare, and these often are segregates of widespread continental species. Because of a lack of resolution at the base of several clades, it is currently not possible to determine which mainland groups are the closest relatives of these Caribbean endemics, thus preventing us from establishing unequivocally the geographical origins of these species.

A REVISION OF BOURRERIA (BORAGINALES, EHRETIACEAE) IN SOUTH AMERICA1

A review of South American herbarium specimens of Bourreria P. Browne (Boraginales, Ehretiaceae) indicates that five species are readily distinguished. Bourreria bolivarensis Gottschling & J. S. Mill. is described as new; B. baccata Raf., B. exsucca Jacq., and B. mollis Standl. have their nomenclature clarified; B. exsucca is epitypified; and a neotype has been designated for Rhamnus cumanensis Loefl. (= B. exsucca). Bourreria bolivarensis and B. exsucca are common species in the northern South American flora. Bourreria costaricensis (Standl.) A. H. Gentry and B. mollis are Central American species that have not been previously reported for South America. Bourreria baccata is a Caribbean species with the southern end of its distribution on Tobago, but it also occurs in a small, isolated population in the Netherlands Antilles and on the adjacent Venezuelan coast, perhaps resulting from a single long-distance dispersal event. Bourreria exsucca and the new species B. bolivarensis have their distribution restricted to South America and exhibit schizocarpous fruits. The other three species have drupaceous fruits. All five species have extent of occurrence above the threshold (> 2000 km2) to be considered vulnerable based on the IUCN Red List categories, and none of the five species that occur in South America appear to be threatened when evaluated solely on their distributions.

Visually guided obstacle avoidance in the box jellyfish Tripedalia cystophora and Chiropsella bronzie

Box jellyfish, cubomedusae, possess an impressive total of 24 eyes of four morphologically different types. Two of these eye types, called the upper and lower lens eyes, are camera-type eyes with spherical fish-like lenses. Compared with other cnidarians, cubomedusae also have an elaborate behavioral repertoire, which seems to be predominantly visually guided. Still, positive phototaxis is the only behavior described so far that is likely to be correlated with the eyes. We have explored the obstacle avoidance response of the Caribbean species Tripedalia cystophora and the Australian species Chiropsella bronzie in a flow chamber. Our results show that obstacle avoidance is visually guided. Avoidance behavior is triggered when the obstacle takes up a certain angle in the visual field. The results do not allow conclusions on whether color vision is involved but the strength of the response had a tendency to follow the intensity contrast between the obstacle and the surroundings (chamber walls). In the flow chamber Tripedalia cystophora displayed a stronger obstacle avoidance response than Chiropsella bronzie since they had less contact with the obstacles. This seems to follow differences in their habitats.

Fishes (Elasmobranchii and Actinopterygii) of Picãozinho reef, Northeastern Brazil, with notes on their conservation status

Shallow reefs on the northeastern coast of Brazil are rich, productive and diverse environments, with great ecological and economical importance. Picãozinho is located 1,500 m off the coast of João Pessoa city, Paraíba state, NE Brazil. The aim of this work is to provide an updated list of the reef fishes of Picãozinho, based on a survey of approximately 350 hours of direct observation using free dive techniques, and complemented by collection data and other unpublished records. A total of 102 species of 43 families were recorded. Of these, 36 are new occurrences for the reef and seven are species that have been recently resurrected from synonymy, mainly with Caribbean species previously cited for Brazil.

Molecular evidence for phylogenetic relationships of Jacquemontia reclinata House (Convolvulaceae) – a critically endangered species from south Florida

Jacquemontia reclinata House (Convolvulaceae) is a federally listed endangered species endemic to coastal strand habitat of south-eastern Florida. In order to identify the closest relatives of J. reclinata, a phylogenetic reconstruction was performed based on nucleotide sequence data from the internal transcribed spacer region of nuclear ribosomal DNA and from the trnH-psbA intergenic spacer of chloroplast DNA. The three putative relatives of J. reclinata and the majority of Jacquemontia Choicy species known to occur in the Caribbean Islands were included. The strict consensus tree concurs with previous morphological studies, indicating that J. reclinata is closely related to the Caribbean species J. cayensis Britton, J. curtisii Hallier f., and J. havanensis (Jacq.) Urb. These three species and J. reclinata form an unresolved clade. Nucleotide divergence within this clade is low, suggesting that the group is recent, perhaps diversifying after the latest glacial period. These taxa need to be studied further using population-level DNA markers. Most species endemic to the Caribbean Basin form a strongly supported clade. Our phylogeny supports Convolvulus nodiflorus Desr. as part of Jacquemontia. In addition, J. ovalifolia (West) Hallier f. ssp. sandwicensis (A. Gray) K.R. Robertson is sister to the Antillean endemic J. solanifolia (L.) Hallier f. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 154, 443-454.

The lens eyes of the box jellyfish Tripedalia cystophora and Chiropsalmus sp. are slow and color-blind

Box jellyfish, or cubomedusae, possess an impressive total of 24 eyes of four morphologically different types. Compared to other cnidarians they also have an elaborate behavioral repertoire, which for a large part seems to be visually guided. Two of the four types of cubomedusean eyes, called the upper and the lower lens eye, are camera type eyes with spherical fish-like lenses. Here we explore the electroretinograms of the lens eyes of the Caribbean species, Tripedalia cystophora, and the Australian species, Chiropsalmus sp. using suction electrodes. We show that the photoreceptors of the lens eyes of both species have dynamic ranges of about 3 log units and slow responses. The spectral sensitivity curves for all eyes peak in the blue-green region, but the lower lens eye of T. cystophora has a small additional peak in the near UV range. All spectral sensitivity curves agree well with the theoretical absorbance curve of a single opsin, strongly suggesting color-blind vision in box jellyfish with a single receptor type. A single opsin is supported by selective adaptation experiments.

Fossil and extant species of the genus Leptopholcus in the Dominican Republic, with the first cases of egg‐parasitism in pholcid spiders (Araneae: Pholcidae)

Representatives of the pholcid spider genus Leptopholcus are extremely rare on the American mainland, but fairly common on the major Caribbean islands. Previously, four extant Caribbean species were known, each one endemic to one of the Greater Antilles. Here we describe the first fossil representative of the genus, Leptopholcus kiskeya Huber and Wunderlich n. sp., originating from Dominican amber about 20 million years old. Two new extant species from the Dominican Republic are also described, L. toma Huber n. sp. and L. baoruco Huber n. sp., and new records are given for the widely distributed L. hispaniola Huber, 2000. Egg‐parasitism by a wasp of the genus Baeus Haliday (Scelionidae, Baeini) is documented for L. baoruco and L. hispaniola. These are the first records of egg‐parasitism in Pholcidae, and the first Neotropical Baeus species to parasitize spiders other than Araneidae and Theridiidae.

Review of the Caribbean species of Dohrniphora Dahl (Diptera: Phoridae)

Based on previous records and newly collected material, we review the species of Dohrniphora of the Caribbean islands, not including Trinidad. Five species are present: D. cornuta (Bigot), D. dispar (Enderlein), D. divaricata (Aldrich) and two new species, D. seriata and D. sexspinosa. We redescribe the three previously known species, and illustrate all with scanning electron micrographs of the posterior face of the hind femur and drawings of the male genitalia. Both of the new species are unusual in having six scutellar setae instead of the usual four. The species D. cavifemur Borgmeier is synonymized with D. divaricata, and the allotype male identified as D. cornuta. A key to the males of Caribbean species of Dohrniphora is provided.

The occurrence of Scolymia cubensis in Brazil: revising the problem of the Caribbean solitary mussids

Identification of scleractinian corals is traditionally based upon morphological analysis of skeleton traits. However, due to the influence of the environment on coral development, and the pattern highly variable of most diagnostical characters, additional information related to anatomy of soft parts, reproductive behavior and ecological interactions have been argued to support the distinction among similar morphotypes. Caribbean and South Atlantic Scolymia comprise a small group of solitary zooxanthellate corals: Scolymia lacera, S. cubensis and S. wellsii have been far subject of taxonomical misunderstandings. Aggressive interactions bewteen S. lacera and S. cubensis were useful to validate their specific status. Nevertheless, S. wellsii has been erroneously suggested to be synonym of S. cubensis. Following Laborel, Lang and Wells’ studies, we reinforce the individuality of the Atlantic Scolymia species, confirming the occurrence of S. cubensis to Brazil. Supporting newly-reported occurrences of Caribbean species along the Brazilian littoral, this finding is likely to contribute with a new perspective to assess the ‘variability’ among scleractinian corals. A key for the identification of the Scolymia species is provided.

The spectral sensitivity of the lens eyes of a box jellyfish,Tripedalia cystophora(Conant)

Box jellyfish, or cubomedusae (class Cubozoa), are unique among the Cnidaria in possessing lens eyes similar in morphology to those of vertebrates and cephalopods. Although these eyes were described over 100 years ago, there has been no work done on their electrophysiological responses to light. We used an electroretinogram (ERG) technique to measure spectral sensitivity of the lens eyes of the Caribbean species Tripedalia cystophora. The cubomedusae have two kinds of lens eyes, the lower and upper lens eyes. We found that both lens eye types have similar spectral sensitivities, which likely result from the presence of a single receptor type containing a single opsin. The peak sensitivity is to blue-green light. Visual pigment template fits indicate a vitamin A-1 based opsin with peak sensitivity near 500 nm for both eye types.

Distribution of behaviours and species interactions within home range contours in five Caribbean reef fish species (Family Labridae)

This study investigated the distribution of behaviours and species interactions within home range contours in five Caribbean labrid species: Halichoeres bivittatus, H. garnoti, H. maculipinna, H. poeyi, and Thalassoma bifasciatum. For this study, contours were defined as: (a) 30%—the core use area, (b) 30–75%—the intermediate activity area, and (c) 75–95%—the peripheral activity area. Behaviours analyzed for this study included: (i) feeding (=biting the substrate or chewing), (ii) chased by pomacentrids, (iii) swimming alone, (iv) swimming with other fishes, and (v) all activities with other fishes. Fifty-nine percent of Halichoeres bivittatus observed showed a higher frequency than expected being chased by pomacentrids in the peripheral region of their home ranges. Halichoeres garnoti showed a lower frequency than expected swimming with other individuals in their core use area, and 64% of the individuals observed showed a higher frequency than expected being chased by pomacentrids in the peripheral region. In general, H. maculipinna exhibited a random distribution of behaviours throughout their home range areas, with a non-significant trend for more agonistic interactions with pomacentrids in peripheral regions. Halichoeres poeyi and T. bifasciatum showed higher frequencies than expected being chased by pomacentrids in the peripheral regions. Overall, the non-random distribution of agonistic interactions with pomacentrids throughout home range areas suggests that the presence or prior residence of territorial pomacentrids on coral reefs may modify the post-settlement selection of home range areas by these labrid species.

A note on the phylogenetic position of Duartettix montanus within the subfamily Melanoplinae

Abstract This research sheds light on the phylogenetic position of the recently described Caribbean species Duartettix montanus. Morphologically most similar to the Melanoplinae, especially the North American genus Melanoplus, it was assigned to that subfamily. The Orthoptera Species File, curiously, assigns Duartettix to the South American tribe Dichroplini. The present molecular phylogenetic analysis of portions of four mitochondrial genes, however, strongly rejects that allocation and instead supports an association with the northern melanoplines. Within the context of an “Out-of-South America” hypothesis proposed earlier for the subfamily's origin, it is speculated that the antecedents of Duartettix arose from ancestors on their northward movement, traversing a series of island arcs that intermittently connected the two Americas during the late Cretaceous. Of possible taxonomic interest, phylogenetic information is also provided for a number of South American melanoplines, notably members of the tribe...

PHYLOGENY AND BIOGEOGRAPHY OF THE ATLANTIC AND EASTERN PACIFIC HYPSELODORIS STIMPSON, 1855 (NUDIBRANCHIA, CHROMODORIDIDAE) WITH THE DESCRIPTION OF A NEW SPECIES FROM THE CARIBBEAN SEA

A new species, based on two specimens from Guana Island, British Virgin Islands, is described. The new species agrees with the genus Hypselodoris in having a high body profile, a large vestibular gland and mantle glands. It differs from other members of the genus in the Atlantic Ocean by having a reddish background body colour. In addition, dorsal colour patterns such as a broad central white line with lateral extensions and the lack of yellow lines or spots further differentiate this species. The radular formula of 52 x 41.0.41 and a smaller seminal receptacle are also distinctive. The phylogenetic relationships of 34 species and subspecies of Hypselodoris from the eastern Pacific and Atlantic are examined using morphological characters. With the exception of the new species, these are characterized by a dark blue background body colour. The phylogenetic analysis of the data matrix resulted in eight most-parsimonious trees. The resulting consensus tree shows that eastern Pacific and Atlantic species of Hypselodoris constitute a monophyletic group that is basally split into two sister clades. One clade contains the eastern Pacific species and most of the Caribbean species, whereas the other clade contains the eastern Atlantic species. The new species is the sister to the rest of the Caribbean species, which also form a monophyletic group. This phylogenetic hypothesis suggests that two consecutive vicariant events have affected the biogeography of Hypselodoris: (1) the closure of communication between the tropical Indo-Pacific region and the Atlantic and eastern Pacific, completed with the formation of the East Pacific Barrier; and (2) the rise of the Panama isthmus.