World Travelers: DNA Barcoding Unmasks the Origin of Cloning Asteroid Larvae from the Caribbean (original) (raw)

Knots, spoons, and cloches: DNA barcoding unusual larval forms helps document the diversity of Neotropical marine annelids

Invertebrate Biology, 2021

The morphological diversity of marine annelid larvae is stunning. Although many of the larval forms have been categorized as trochophores or modified trochophores there are a few groups with distinctive larval features that make them easy to distinguish from other annelid larvae. We collected 252 annelid larvae from the plankton, with particular emphasis on oweniids, polygordiids, and thalassematids (i.e., echiurans) and sequenced fragments of their cytochrome c oxidase subunit 1 and 16S ribosomal RNA genes. We found 6 oweniid, 5 polygordiid, and 8 thalassematid OTUs. Thalassematids were found only in samples from the Pacific, while oweniids were found only in Caribbean samples. Among the oweniids we found two distinct morphotypes, one with a narrow, cloche shape and another that had a wider and more rectangular shape with clearly-developed lappets. Among the polygordiids we identified one larva as Polygordius eschaturus and several larvae as Polygordius jenniferae . All larvae, exc...

How I wonder what you are: Can DNA barcoding identify the larval asteroids of Panama?

Invertebrate Biology, 2020

As part of a project to document the diversity of larval invertebrates on both coasts of Panama, we collected and photographed 141 larval asteroids and sequenced fragments of their mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal DNA. We uncovered 10 Caribbean operational taxonomic units (OTUs) and five Pacific OTUs. We could identify six of the 15 OTUs based on >99% similarity with reference sequences in GenBank: The Pacific species Astropecten verrilli and Pentaceraster cumingi and the Caribbean species Astropecten marginatus, Astropecten antillensis, Oreaster reticulatus, and Mithrodia clavigera. Two other OTUs were placed in BINs in the Barcode of Life Database (BOLD) with unpublished sequences that were identified as Pharia pyramidata from the Pacific and Valvaster striatus, now known from the Caribbean as well as the Indo‐West Pacific. The remaining seven species appear likely to belong to Luidia, as 16S sequences from each have 87%–95% identity with var...

Discovery of Adults Linked to Cloning Oceanic Starfish Larvae (Oreaster, Asteroidea: Echinodermata)

The Biological Bulletin, 2019

Two juvenile specimens of a new species of Oreaster were collected at Parque Nacional Arrecife Alacranes and Triángulos Oeste in the southern Gulf of Mexico. DNA of mitochondrial loci identifies them as members of the same clade as cloning larvae of Oreaster found abundantly in waters of the Florida Current-Gulf Stream system, and distinct from Oreaster clavatus and Oreaster reticulatus, the two known Oreasteridae species in the North Atlantic. Larvae from the new species of Oreaster persist as clones but also metamorphose and settle to the benthos with typical asteroid morphology.

Lack of genetic evidence for the subspeciation of Pisaster ochraceus (Echinodermata: Asteroidea) in the north-eastern Pacific Ocean

Journal of The Marine Biological Association of The United Kingdom, 2008

The existence of two Pisaster ochraceus subspecies has been proposed; one located northwards (P. ochraceus ochraceus) and the other southwards (Pisaster ochraceus segnis) from Point Conception. We used polymerase chain reaction -restriction fragment length polymorphism of the CO I and CO III mitochondrial genes to assess the degree of population structure from 126 samples collected along the western coast of North America, from Vancouver, Canada to Punta San Carlos, of Baja California, Mexico. The genetic structure was tested through molecular analysis of variance and by Monte Carlo simulations of the original data set. The phylogeographical pattern was deduced from a minimum spanning network analysis. No genetic structure was detected. Instead, a high degree of genetic homogeneity along the species distribution was evident from haplotype frequencies at each location. Two haplotypes, Po1 and Po5, were predominant along the distribution and were considered ancestral because of their central position in the minimum spanning network. Since Pisaster ochraceus depicts a planktotrophic larval stage with very long duration before settlement, it seems to be able to surpass the biogeographical boundary that limits other species around Point Conception, thereby maintaining homogeneity of its genetic pool. Results of this study recognize P. ochraceus as a single species.

DNA barcoding of reef brittle stars (Ophiuroidea, Echinodermata) from the southwestern Indian Ocean evolutionary hot spot of biodiversity

Ecology and evolution, 2017

In anticipation of the current biodiversity crisis, it has become critical to rapidly and accurately assess biodiversity. DNA barcoding has proved efficient in facilitating the discovery and description of thousands of species and also provides insight into the dynamics of biodiversity. Here, we sequenced a portion of the mitochondrial cytochrome c oxidase subunit I (COI) gene from all morphospecies of reef brittle stars collected during a large-scale biodiversity survey in the southwestern Indian Ocean (SWIO). Three methods of species delineation (Automatic Barcode Gap Discovery, Generalized Mixed Yule Coalescent model, and Bayesian Poisson Tree Processes) showed concordant results and revealed 51 shallow reef species in the region. Mean intraspecific genetic distances (0.005-0.064) and mean interspecific genetic distances within genera (0.056-0.316) were concordant with previous echinoderm studies. This study revealed that brittle-star biodiversity is underestimated by 20% within ...

Complete mitochondrial genome of a sea star, Linckia laevigata (Echinodermata, Asteroidea, Valvatida, Ophidiasteridae)

Mitochondrial DNA Part B, 2020

We determined the complete mitochondrial genome sequences of an asteroid Linckia laevigata belonging to the order Valvatida. The complete mitogenome of L. laevigata was 16,371 bp in length and consisted of 13 protein-coding genes (PCGs), two rRNA, and 22 tRNA. The orders of PCGs and rRNAs were identical to those of the recorded mitogenomes of asteroids. Phylogenetic analyses placed L. laevigata as the sister group to the species of the other Paxillosida.

Molecular data and biogeography: resolution of a controversy over evolutionary history of a pan-tropical group of invertebrates

Journal of Experimental Marine Biology and Ecology, 1996

Phylogenetic analyses of sequences of 16s rDNA suggest that the current hypothesis of the evolution of the pan-tropical fiddler crab genus Uca (Decapoda, Brachyura, Ocypodidae) is false. This hypothesis rests of the assumption that the increase of complexity of reproductive behavior, together with a tendency of a habitat shift towards the higher intertidal, arose only once in the history of the fiddler crabs. The origin of fiddler crabs was placed in the IndoPacific, which is widely thought to be a center of origin for several marine groups. There, relatively lower intertidal crabs were thought to give rise to a radiation in the Americas in which higher intertidal forms with more complex reproductive behavior evolved, and finally, derived crabs were thought to disperse back to the IndoPacific from the Americas. In contrast our phylogeny suggests that the ancestral group, which shows complex reproductive behavior, now resides wholly in the American-Atlantic region, as opposed to the postulated Indo-west-Pacific. Behavioral and ecological complexity must have arisen independently in the American and IndoPacific fauna1 regions. The pan-tropical subgenus Celuca seems to be polyphyletic, which suggests that the evolution of morphology, ecology and behavior involves convergence in geographically separated locales. This study highlights the dangers of postulating evolution from a center of origin, even if it fits data that can be assigned to an evolutionary trend.

Documenting neotropical diversity of phoronids with DNA barcoding of planktonic larvae

Invertebrate Biology, 2019

Phoronid larvae, actinotrochs, are beautiful and complicated organisms which have attracted as much, if not more, attention than their adult forms. We collected actinotrochs from the waters of the Pacific and Caribbean coasts of Panama, and used DNA barcoding of mtCOI, as well as 16S and 18S sequences, to estimate the diversity of phoronids in the region. We discovered three operational taxonomic units (OTUs) in the Bay of Panama on the Pacific coast and four OTUs in Bocas del Toro on the Caribbean coast. Not only did all OTUs differ from each other by >10% pairwise distance in COI, but they also differed from all phoronid sequences in GenBank, including the four species for which adults have been reported for the Pacific of Panama, Phoronopsis harmeri, Phoronis psammophila, Phoronis muelleri, and Phoronis hippocrepia. In each ocean region, one common OTU was more abundant and occurred more frequently than other OTUs in our samples. The other five OTUs were relatively rare, with only one to three individuals collected during the entire project. Species accumulation curves were relatively flat but suggest that at least one more species is likely to be present at each site. Actinotrochs from the seven sequenced OTUs had morphologies typical of species with non-brooded planktotrophic development and, in some cases, may be distinguished by differences in pigmentation and the arrangement of blood masses. We found one larva with morphology typical of brooded planktotrophic larvae for which sequencing failed, bringing the total number of potential species detected to eight and representing >50% of the adult species currently recognized globally.

Molecular phylogenetics reveals first record and invasion of Saccostrea species in the Caribbean

Marine Biology, 2015

data from the mitochondrial cytochrome oxidase I gene were combined with morphological criteria to confirm the identities of ten oyster species of Ostreidae, Isognomonidae, and Pteriidae, focusing on the Pacific and Caribbean coasts of Panama, since tropical biota have received the least study. The results indicate that Crassostrea virginica, previously only reported from this region along the Yucatan Peninsula and coast of Venezuela, also occurs in the Caribbean waters of Panama. We also document the first record for a species of Saccostrea, a genus native to the Pacific, suggesting an invasion by an unknown non-native Saccostrea species that is now widespread along the Caribbean from the Panama Canal west to Bocas del Toro. Sequences of the internal transcribed spacer region (ITS1) of the ribosomal gene complex (rDNA) did not reveal any hybridization. Considering the high connectivity of shipping and boating in Panama, Saccostrea sp. may have been introduced to the Caribbean by either recreational or commercial vessels, but the timing and potential ecological effects of this invasion remain unknown. Communicated by C. Riginos.

Documenting decapod biodiversity in the Caribbean from DNA barcodes generated during field training in taxonomy

DNA barcoding is a useful tool to identify the components of mixed or bulk samples, as well as to determine individuals that lack morphologically diagnostic features. However, the reference database of DNA barcode sequences is particularly sparsely populated for marine invertebrates and for tropical taxa. We used samples collected as part of two field courses, focused on graduate training in taxonomy and systematics, to generate DNA sequences of the barcode fragments of cytochrome c oxidase subunit I (COI) and mitochondrial ribosomal 16S genes for 447 individuals, representing at least 129 morphospecies of decapod crustaceans. COI sequences for 36% (51/140) of the species and 16S sequences for 26% (37/140) of the species were new to GenBank. Automatic Barcode Gap Discovery identified 140 operational taxonomic units (OTUs) which largely coincided with the morphospecies delimitations. Barcode identifications (i.e. matches to identified sequences) were especially useful for OTUs within Synalpheus, a group that is notoriously difficult to identify and rife with cryptic species, a number of which we could not ‡, § | ¶ § § ‡ © Venera-Pontón D et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.