Phylogeny

A new species of frog from the Caribbean island of Montserrat (Eleutherodactylidae, Eleutherodactylus)

Abstract

I describe a new species of frog, Eleutherodactylus montserratae sp. nov., from Montserrat, previously confused with E. johnstonei Barbour. It is native to that island and has been introduced, and established, on other Lesser Antillean islands west of 62 degrees west longitude including Anguilla, St. Martin/St. Maarten, St. Barthélemy, Saba, St. Eustatius, St. Christopher, and Nevis, as well as Bermuda. Previous chromosome and molecular studies have shown that populations from these islands are distinct from E. johnstonei, a species occurring east of 62 degrees west longitude in the Lesser Antilles, and elsewhere, but could not identify diagnostic morphological differences. Here, I show that the new species differs morphologically in being smaller (males and females) and having a proportionately larger tympanum, a wider head, and greater separation between the nostrils. Both species have been introduced within and outside of the Caribbean region and will likely expand their ranges in the future.

 

https://www.mapress.com/zt/article/view/zootaxa.5219.4.5

 

Date
2022
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Saba
St. Eustatius
St. Maarten

New Records of the Cryptogenic Soft Coral Genus Stragulum (Tubiporidae) from the Eastern Caribbean and the Persian Gulf

Abstract

The monotypic soft coral genus Stragulum van Ofwegen and Haddad, 2011 (Octocorallia: Malacalcyonacea: Tubiporidae) was originally described from Brazil, southwest Atlantic Ocean. Here, we report the first records of the genus from the eastern Caribbean and the Persian Gulf in the northwest Indian Ocean. We compare the morphological features of specimens, together with molecular data from three commonly used barcoding markers (COI, mtMutS, 28S rDNA) and 308 ultraconserved elements (UCE) and exon loci sequenced using a target-enrichment approach. The molecular and morphological data together suggest that specimens from all three localities are the same species, i.e., Stragulum bicolor van Ofwegen and Haddad, 2011. It is still not possible to establish the native range of the species or determine whether it may be an introduced species due to the limited number of specimens included in this study. However, the lack of historical records, its fouling abilities on artificial substrates, and a growing number of observations support the invasive nature of the species in Brazilian and Caribbean waters and therefore suggest that it may have been introduced into the Atlantic from elsewhere. Interestingly, the species has not shown any invasive behaviour in the Persian Gulf, where it has been found only on natural, rocky substrates. The aim of the present report is to create awareness of this taxon with the hope that this will lead to new records from other localities and help to establish its native range

Date
2022
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
St. Maarten

Painted black: Iguana melanoderma (Reptilia, Squamata, Iguanidae) a new melanistic endemic species from Saba and Montserrat islands (Lesser Antilles)

Abstract

 

The Lesser Antilles, in the Eastern Caribbean, is inhabited by three Iguana species: the Lesser Antillean iguana Iguana delicatissima, which is endemic to the northernmost islands of the Lesser Antilles, the introduced common iguana from South America, Iguana iguana iguana, represented also by the two newly described endemic subspecies Iguana iguana sanctaluciae from Saint Lucia and Iguana iguana insularis from Saint Vincent and the Grenadines, and Grenada, and the introduced Iguana rhinolopha from Central America. Drawing on both morphological and genetic data, this paper describes the Iguana populations from Saba and Montserrat as a new species, Iguana melanoderma. This species is recognized on the basis of the following combination of characteristics: private microsatellite alleles, unique mitochondrial ND4 haplotypes, a distinctive black spot between the eye and tympanum, a dorsal carpet pattern on juveniles and young adults, a darkening of body coloration with aging (except for the anterior part of the snout), a black dewlap, pink on the jowl, the high number of large tubercular nape scales, fewer than ten medium sized–triangular dewlap spikes, high dorsal spikes, and lack of horns on the snout. This new melanistic taxon is threatened by unsustainable harvesting (including for the pet trade) and both competition and hybridization from escaped or released invasive alien iguanas (I. iguana iguana and I. rhinolopha) from South and Central America, respectively. The authors call for action to conserve Iguana melanoderma in Saba and Montserrat and for further research to investigate its relationship to other melanistic iguanas from the Virgin Islands and coastal islands of Venezuela.

 

Keywords: Conservation Biology, Iguana, Lesser Antilles, microsatellites, mtDNA, new endemic species, phylogeny

Date
2020
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Saba

A taxonomist‘s nightmare – Cryptic diversity in Caribbean intertidal arthropods (Arachnida, Acari, Oribatida)

Abstract

There has been a long controversy about what defines a species and how to delimitate them which resulted in the existence of more than two dozen different species concepts. Recent research on  so-called “cryptic species” heated up this debate as some scientists argue that these cryptic species are only a result of incompatible species concepts. While this may be true, we should keep in mind that all concepts are nothing more than human constructs and that the phenomenon of high phenotypic similarity despite reproductive isolation is real. To investigate and understand this phenomenon it is important to classify and name cryptic species as it allows to communicate them with other fields of science that use Linnaean binomials. To provide a common framework for the description of cryptic species, we propose a possible protocol of how to formally name and describe these taxa in practice. The most important point of this protocol is to explain which species concept was used to delimitate the cryptic taxon. As a model, we present the case of the allegedly widespread Caribbean intertidal mite Thalassozetes barbara, which in fact consists of seven phenotypically very similar but genetically distinct species. All  species are  island or  short-range endemics with poor dispersal abilities that have evolved in geographic isolation. Stabilizing selection caused by the extreme conditions of the intertidal environment is suggested to be responsible for the morphological stasis of this cryptic species complex.

Date
2021
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Curacao

The role of mimicry within congruencies amongst herbivorous and carnivorous fish in Bonaire

Mimetic behavior signifies organisms evolving to share behaviors and a common resemblance despite different phylogeny. Relationships in mimicry rely on the characteristics of mimics and models: appearance and size, vertical and geographical distribution, mimic to model abundance, behavioral shifts of the mimic and observed benefits. Using these criteria, species from the Hypoplectrus genus (hamlets) were analyzed as potential aggressive mimics. Using a visual census, the distribution of each mimic and model were surveyed and behaviors of individuals within the mimetic pairs were video recorded. There was 80-94% difference between the population densities of two potential mimetic pairs: Hypoplectrus nigricans (black hamlet) and Stegastes adustus, (dusky damselfish) and Hypoplectrus unicolor (butter hamlet) and Chaetodon capistratus (foureye butterflyfish). Data collected for the potential mimetic pair, Hypoplectrus chlorurus (yellowtail hamlet) and Microspathodon chyrsurus (yellowtail damselfish) does not support the hypothesis because the population density of the supposed mimic was higher than that of the potential model. In addition, for all studied pairs, no notable behavioral shifts were observed, and therefore whether the studied pairs are cases of mimicry is still a question.

This student research was retrieved from Physis: Journal of Marine Science XVII (Spring 2015)19: 43-50 from CIEE Bonaire.

Date
2015
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

A new Liopropoma sea bass (Serranidae, Epinephelinae, Liopropomini) from deep reefs off Curaçao, southern Caribbean, with comments on depth distributions of western Atlantic liopropomins

Abstract

Collecting reef-fish specimens using a manned submersible diving to 300 m off Curaçao, southern Caribbean, is resulting in the discovery of numerous new fish species. The new Liopropoma sea bass described here differs from other western Atlantic members of the genus in having VIII, 13 dorsal-fin rays; a moderately indented dorsal-fin margin; a yellow-orange stripe along the entire upper lip; a series of approximately 13 white, chevron-shaped markings on the ventral portion of the trunk; and a reddish-black blotch on the tip of the lower caudal-fin lobe. The new species, with predominantly yellow body and fins, closely resembles the other two “golden basses” found together with it at Curaçao: L. aberransand L. olneyi. It also shares morphological features with the other western Atlantic liopropomin genus, Bathyanthias. Preliminary phylogenetic data suggest that western Atlantic liopropomins, including Bathyanthias, are monophyletic with respect to Indo-Pacific Liopropoma, and that Bathyanthias is nested within Liopropoma, indicating a need for further study of the generic limits of Liopropoma. The phylogenetic data also suggest that western Atlantic liopropomins comprise three monophyletic clades that have overlapping depth distributions but different depth maxima (3–135 m, 30–150 m, 133–411 m). The new species has the deepest depth range (182–241 m) of any known western Atlantic Liopropomaspecies. Both allopatric and depth-mediated ecological speciation may have contributed to the evolution of western Atlantic Liopropomini.

 

 

 

Date
2014
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Curacao

A new, mesophotic Coryphopterus goby (Teleostei, Gobiidae) from the southern Caribbean, with comments on relationships and depth distributions within the genus

A new species of western Atlantic Coryphopterus is described from mesophotic depths off Curaçao, south- ern Caribbean. Coryphopterus curasub sp. n., is similar to C. dicrus in, among other features, having two prominent pigment spots of roughly equal intensity on the pectoral-fin base, the pelvic fins fused to form a disk, and no pelvic frenum. The two species can be differentiated by body depth (shallower in C. curasub at origin of dorsal fin and caudal peduncle); differences in the pigmentation on the head, trunk, and ba- sicaudal region; and usually by total number of rays (spinous plus soft) in the second dorsal fin (10–11, usually 11, in C. curasub, 10 in C. dicrus). Coryphopterus curasub differs from other Coryphopterus species that have a prominent pigment spot on the lower portion of the pectoral-fin base (C. punctipectophorus and C. venezuelae) in, among other features, lacking a pelvic frenum. Coryphopterus curasub was collected between 70 and 80 m, the deepest depth range known for the genus. Collections of C. venezuelae at depths of 65–69 m extend the depth range of that species by approximately 50 m. Mitochondrial cytochrome c oxidase subunit I (COI) data corroborate the recognition of C. curasub as a distinct species but do not rigorously resolve its relationships within the genus. A revised key to the western Atlantic species of Cor- yphopterus is presented. 

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Curacao