Cryptic species

Unveiling Hidden Communities with FARMS

Dutch below

A collaborative study, led by the University of Texas at Austin, deployed 102 specialized fish monitoring structures across six locations, including the deep reefs of Curacao.  The goal of this study was to identify a standardized simple and effective way to survey small, bottom-dwelling fish populations.

From shallow tide pools to the deep sea, unique evolutionary traits allow fish to occupy every corner of the ocean. Historically, fish populations have been tracked using visual surveys, which can often overlook small or bottom-associated (cryptobenthic) species. A collaborative study, led by the University of Texas at Austin, explored a new technique to quantify these difficult to find species by utilizing a Fish-specific Autonomous Reef Monitoring Structures (FARMS).

FARMS

These FARMS are specifically created using easily accessible and affordable materials. Through a combination of stacked PVC pipes and mesh baskets, FARMS can be deployed in a wide variety of locations to investigate these cryptobenthic populations.  Although FARMS may not fully replicate the surrounding environment, especially in habitats with no solid structures, this study did find these structures to be an efficient technique for sampling local diversity, capturing a higher number of species per unit area compared to other methods.

Curacao

During this study, FARMS were deployed across six locations (Hawaii, Texas, Panama, Saudi Arabia, Brazil and Curacao). The FARMS deployed off Curacao were used to explore deeper areas of reef, placed at 60m, 146m and 223m depth. Due to the limitations for SCUBA-based research, deep reefs are some of the least explored ecosystems and the vast majority of deep reef research has relied on visual counts. Accordingly, one of the FARMS captured a species of goby (Psilotris laurae) which has never before been documented on Curacao. This highlights the ability of these systems to provide a new, improved way of sampling populations, particularly in deep or hard to reach locations.

Fish species found using FARMS. Photo credit: Simon Brandl

Impacts

Overall, FARMS are considered a simple, standardized, and cost-effective technique for studying cryptobenthic fish communities in habitats where other sampling methods are considered impractical or restricted. The study highlighted the potential of FARMS for exploring under sampled habitats, such as deep reefs, where they could contribute to the discovery of new species and enhance our understanding of cryptobenthic fish diversity and distribution patterns.

DCNA

The Dutch Caribbean Nature Alliance (DCNA) supports science communication and outreach in the Dutch Caribbean region by making nature-related scientific information more widely available through amongst others the Dutch Caribbean Biodiversity Database, DCNA’s news platform BioNews and the press. This article contains the results from several scientific studies but the studies themselves are not DCNA studies. No rights can be derived from the content. DCNA is not liable for the content and the (in) direct impacts resulting from publishing this article.

 

 

Een collaboratieve studie, geleid door de University of Texas in Austin, heeft 102 gespecialiseerde structuren voor het monitoren van vissen ingezet op zes locaties, waaronder de diepe riffen van Curaçao. Het doel van deze studie was om een gestandaardiseerde, eenvoudige en effectieve manier te vinden om kleine, op de bodem levende vispopulaties te onderzoeken.

Van ondiepe getijdenpoelen tot de diepzee, dankzij unieke evolutionaire eigenschappen kunnen vissen elke hoek van de oceaan bezetten. Historisch gezien zijn vispopulaties gevolgd met behulp van visuele onderzoeken, die vaak kleine of met de bodem geassocieerde (cryptobenthische) soorten over het hoofd kunnen zien. Een gezamenlijke studie, geleid door de University of Texas in Austin, onderzocht een nieuwe techniek om deze moeilijk te vinden soorten te kwantificeren door gebruik te maken van een visspecifieke autonome rif monitor structuur (FARMS).

FARMS

Deze FARMS zijn speciaal gemaakt met behulp van gemakkelijk toegankelijke en betaalbare materialen. Door een combinatie van gestapelde PVC-buizen en gaasmanden kan FARMS op een groot aantal verschillende locaties worden ingezet om deze cryptobenthische populaties te onderzoeken. Hoewel FARMS de omgeving mogelijk niet volledig nabootsen, vooral in habitats zonder vaste structuren, vond deze studie deze structuren een efficiënte techniek voor het bemonsteren van lokale diversiteit, waarbij een groter aantal soorten per oppervlakte-eenheid werd gevangen in vergelijking met andere methoden.

Curaçao

Tijdens dit onderzoek werden FARMS ingezet op zes locaties (Hawaii, Texas, Panama, Saoedi-Arabië, Brazilië en Curaçao). De FARMS die buiten Curaçao werden ingezet, werden gebruikt om diepere delen van het rif te verkennen, geplaatst op 60 meter, 146 meter en 223 meter diepte. Vanwege de beperkingen van SCUBA-gebaseerd onderzoek, zijn diepe riffen een van de minst onderzochte ecosystemen en de overgrote meerderheid van diep rifonderzoek is gebaseerd op visuele tellingen. Niet geheel onverwachts ving een van de FARMS dan ook een soort grondel (Psilotris laurae) die nog nooit eerder op Curaçao was gedocumenteerd. Dit benadrukt de capaciteit van deze systemen om een nieuwe, verbeterde manier te bieden om populaties te bemonsteren, met name op diepe of moeilijk bereikbare locaties.

Vissoorten gevonden met FARMS. Foto: Simon Brandl

Effecten

Over het algemeen worden FARMS beschouwd als een eenvoudige, gestandaardiseerde en kosteneffectieve techniek voor het bestuderen van cryptobenthische visgemeenschappen in habitats waar andere bemonsteringsmethoden als onpraktisch of beperkt worden beschouwd. De studie benadrukte het potentieel van FARMS voor het verkennen van onder bemonsterde habitats, zoals diepe riffen, waar ze kunnen bijdragen aan de ontdekking van nieuwe soorten en ons begrip van de diversiteit en verspreidingspatronen van cryptobenthische vissen kunnen vergroten.

DCNA

De Dutch Caribbean Nature Alliance (DCNA) ondersteunt wetenschapscommunicatie en outreach in de Nederlandse Caribische regio door natuurgerelateerde wetenschappelijke informatie breder beschikbaar te maken via onder meer de Dutch Caribbean Biodiversity Database, DCNA’s nieuwsplatform BioNews en de pers. Dit artikel bevat de resultaten van verschillende wetenschappelijke onderzoeken, maar de onderzoeken zelf zijn geen DCNA-onderzoeken. Aan de inhoud kunnen geen rechten worden ontleend. DCNA is niet aansprakelijk voor de inhoud en de (in)directe gevolgen die voortvloeien uit het publiceren van dit artikel.

 

 

 

Published in BioNews 67

Date
2023
Data type
Media
Theme
Education and outreach
Geographic location
Curacao
Author

Understanding cryptic coral diversity: A 3Dreefscape genomics approach to assess dispersal dynamics and niche differentiation

Abstract  Corals provide habitat for numerous marine species and ecosystem services for global human populations. However, they are vulnerable to local and global scale threats, especially climate change. Measuring demographic processes such as dispersal and ecological processes such as niche partitioning are important for predicting their responses to disturbances and environmental change. So far, correlations between coral genetics and the environment or spatial scale have largely been made over large habitat distinctions, such as depth, reef zone, and among islands or geographic regions. Reefs comprise structurally heterogenous landscapes and thus microhabitats may vary considerably, however, we have little understanding of how genotypes are distributed within reefs across fine spatial scales. Dynamics at fine spatial scales are particularly important in corals due to the frequent discovery of genetically divergent but morphologically indistinguishable coral taxa found sympatrically within reefs (i.e., cryptic taxa, often with no obvious environmental distinctions) and evidence that dispersal distances may be small for some taxa. Technological advancements in both genomic sequencing and underwater imaging and computation can help to study fine-scale dispersal and determine whether cryptic taxa are ecologically partitioned. Reduced representation sequencing can be conducted on wild populations and gives access to genomic variation across hundreds of individuals. Structure-from-motion photogrammetry enables the characterisation of structural features of the reef and coral colonies within reefs; thus, it is possible to combine high resolution spatial mapping and micro-environment analyses with genotyped colonies using these two technologies. 

Species of the Caribbean hard coral genus Agaricia (Order: Scleractinia) are arrayed over the entire depth range for photosynthetically dependent organisms, making them an ideal target for comparing mesophotic (>30 m depth) and shallow (<30 m) species, evaluating microhabitat differentiation, and assessing spatial structures across depths. My thesis uses this genus to explore questions related to spatial and environmental differentiation between and within taxa at scales from tens of kilometres to centimetres. The first data chapter (Chapter 2) of my thesis focuses on two mesophotic-occurring species: Agaricia grahamae and A. lamarcki. Despite presuming to be brooders with localised dispersal, no spatial population genetic structure was found over 10s of kms in either species. However, two sympatrically occurring cryptic taxa within each species were found. In A. lamarcki these taxa exhibited incomplete depth partitioning between shallow and mesophotic depths, yet taxa within A. grahamae displayed no obvious environmental distinctions. Demographic histories of all taxa were characterised by gene flow among taxa. This chapter exemplifies the complexities found in corals, where (1) spatial genetic structures do not follow expectations, (2) morphologically similar, sympatric taxa exist both at the same depths and differentiated by shallow and mesophotic depths and (3) gene flow among taxa may be important for the evolution of corals. My second and third data chapters (Chapters 3 and 4) focus on fine-scale characterisation of genotypes across 3D-imaged reefscapes within three depth zones (5, 10, 20 m) and among four sites along the leeward side of Curaçao and spread over ~50 km. Chapter 3 describes the delineation of cryptic coral taxa and investigates dispersal within and between depths among all taxa. The cryptic taxa are defined by divergent genotypic clusters occurring sympatrically and some were found to be associated with particular depth profiles. Disparate spatial genetic structures were found among congeners, where taxa within A. agaricites and A. humilis presented isolation-by-distance and dispersal distances across metres and, in contrast, A. lamarcki taxa presented genetic homogeneity at distances >50 km. This chapter provides one of the few estimates of dispersal distances in corals, which is exceedingly low (across metres), highlights the widespread cryptic diversity within corals and finds substantial differences in dispersal, clonality and genetic diversity among congeners. In Chapter 4, I used photogrammetry to characterise the microhabitat around individually genotyped colonies of Agaricia by deriving novel geometric measures. Environmental niches for sympatric cryptic taxa were determined by describing microhabitats that coral colonies inhabit. Species and cryptic taxa exhibited subtle divergences in their physical microhabitat niches. This chapter tackles the question of how cryptic coral taxa co-occur in seemingly similar environments and demonstrates a novel photogrammetric approach to characterise the microhabitat. 

My thesis applies new technologies and methods to help solve some of the mysteries of corals populations, namely, how far do larvae disperse? And what creates or preserves cryptic taxa? And in doing so, provides insight into coral ecology (interaction with microhabitat, spatial distribution, and dispersal) and evolution (cryptic diversification and hybridisation).

 

Date
2023
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire
Curacao

First official record of Least Gecko on Saba in 60 years

Dutch below

The Least Gecko was just recorded on Saba for the first time in 60 years.  Identified by researchers from the University of California Davis and the California Academy of Sciences, these sightings serve as the first official records since specimens were collected in 1963. The native versus introduced status of this species on Saba is still unknown, creating potential issues for conservation planning in the future. 

Least Gecko (Sphaerodactylus sputator). Photo credit: Michael Lihan Yuan

The islands of the Caribbean each offer their own unique oasis to a wide variety of species.  Although the islands may appear similar, thousands of years of isolation have allowed many species to evolve to match their surroundings.  This is certainly the case for many types of Lesser Antillean reptiles. Most islands are home to at least one locally endemic species, not found anywhere else.  One example is the Least Gecko (Sphaerodactylus sputator) not to be confused with the Saban Least Gecko (Sphaerodactylus sabanus).

 

New Reports

A recent survey, conducted by scientists from the University of California Davis and California Academy of Sciences, confirmed the presence of the Least Gecko on Saba for the first time since 1963. In October 2021, two individuals were photographed, and genetic samples taken for confirmation.  Both geckos were found on human-constructed stone walls, among what appeared to be many others of the same species.  It is still unclear if this species is native to the island, or introduced in recent history.  Although there are no previous records of this species from the island in guide books or scientific literature, there are two known specimens at the Museum of Comparative Zoology at Harvard University that were collected from Saba in 1963.

 

Gecko Mystery

The location and date of the 1963 specimens provide interesting pieces to this puzzle.  1963 was the year Saba’s airport began operation, so it is unlikely that the airport was the site of introduction for this species because the specimens were collected from the opposite side of the island.  Furthermore, these specimens was said to have been collected along the road to Fort Bay, but Fort Bay itself was not constructed until 1972.  Therefore, if the species is indeed introduced, it is most likely that these specimens (or their earlier relatives) entered the island via Ladder Bay.

Least Gecko (Sphaerodactylus sputator). Photo credit: Michael Lihan Yuan

Understanding the native ranges of species is important not only for conservation and management purposes, but also for achieving a better understanding of their life cycles and evolution. Furthermore, the potential expansion of the Least Gecko’s range to include Saba is unlikely a conservation concern for the island, as the least gecko and Saban least gecko live together on other Caribbean islands without issue.

To learn more, you can find the full report here.

 

The DCNA

The DCNA supports science communication and outreach in the Dutch Caribbean region by making nature related scientific information more widely available through amongst others the Dutch Caribbean Biodiversity Database, DCNA’s news platform BioNews and through the press. This article contains the results of one of those scientific studies but the study itself is not a DCNA study. No rights can be derived from the content. DCNA is not liable for the content and the in(direct) impacts resulting from publishing this article.

 

 

 

De Least Gecko is zojuist voor het eerst in 60 jaar op Saba vastgelegd. Geïdentificeerd door onderzoekers van de University of California, Davis en de California Academy of Sciences, dienen deze waarnemingen als de eerste officiële waarneming sinds er in 1963 exemplaren werden verzameld. De officiële inheemse versus geïntroduceerde status van deze soort op Saba is nog onbekend, waardoor potentiële problemen kunnen ontstaan voor natuurbehoud in de toekomst.

Least Gecko (Sphaerodactylus sputator). Photo credit: Michael Lihan Yuan

De eilanden van het Caribisch gebied bieden elk hun eigen unieke oase aan een grote verscheidenheid aan diersoorten. Hoewel de eilanden op elkaar lijken, hebben duizenden jaren van isolatie ervoor gezorgd dat veel soorten zich hebben kunnen ontwikkelen om zich aan te passen aan hun omgeving. Dit geldt zeker voor veel soorten Klein-Antilliaanse reptielen. De meeste eilanden zijn de thuisbasis van ten minste één lokaal endemische soort, die nergens anders voorkomt. Een voorbeeld is de Least Gecko (Sphaerodactylus sputator), niet te verwarren met de Saban Least Gecko (Sphaerodactylus sabanus).

 

Nieuwe rapporten

Een recent onderzoek, uitgevoerd door wetenschappers van de University of California, Davis en California Academy of Sciences, heeft onlangs voor het eerst sinds 1963 de aanwezigheid van de Least Gecko op Saba bevestigd. In oktober 2021 werden twee individuen gefotografeerd en er werden genetische monsters genomen voor bevestiging. Beide gekko’s werden gevonden op door mensen gebouwde stenen muren, tussen wat leek op vele anderen van dezelfde soort. Het is nog steeds onduidelijk of deze soort inheems is op het eiland, of in de recente geschiedenis is geïntroduceerd. Hoewel er geen eerdere vermeldingen van deze soort op het eiland zijn in gidsen of wetenschappelijke literatuur, zijn er twee exemplaren bekend in het Museum of Comparative Zoology aan de Harvard University die in 1963 op Saba werden verzameld.

 

Gekko mysterie

De locatie en datum van de exemplaren uit 1963 vormen interessante stukjes voor deze puzzel. 1963 was het jaar waarin de luchthaven van Saba in gebruik werd genomen, dus het is onwaarschijnlijk dat de luchthaven de introductieplaats voor deze soort was, omdat de exemplaren werden verzameld vanaf de andere kant van het eiland. Bovendien zouden deze exemplaren langs de weg naar Fort Bay zijn gevonden, maar Fort Bay zelf werd pas in 1972 gebouwd. Als de soort inderdaad werd geïntroduceerd, is het dus zeer waarschijnlijk dat deze exemplaren (of hun eerdere verwanten) het eiland zijn binnengekomen via Ladder Bay.

Least Gecko (Sphaerodactylus sputator). Photo credit: Michael Lihan Yuan

Het begrijpen van de inheemse verspreidingsgebieden van soorten is niet alleen belangrijk voor instandhoudings- en beheersdoeleinden, maar ook voor het verkrijgen van een beter begrip van hun levenscycli en evolutie. Bovendien is de mogelijke uitbreiding van het verspreidingsgebied van de Least Gecko naar Saba onwaarschijnlijk een zorg voor het eiland, aangezien de Least Gecko en de Saban Least Gecko zonder problemen samenleven op andere Caribische eilanden.

Voor meer informatie kunt u het volledige rapport vinden via de link. 

 

De DCNA

De DCNA ondersteunt wetenschapscommunicatie en bereik in de Nederlandse Caribische regio door natuurgerelateerde wetenschappelijke informatie breder beschikbaar te maken via onder meer de Dutch Caribbean Biodiversity Database, DCNA’s nieuwsplatform BioNews en via de pers. Dit artikel bevat de resultaten van een van die wetenschappelijke onderzoeken, maar het onderzoek zelf is geen DCNA-onderzoek. Aan de inhoud kunnen geen rechten worden ontleend. DCNA is niet aansprakelijk voor de inhoud en de indirecte gevolgen die voortvloeien uit het publiceren van dit artikel.

 

Published in BioNews 62

 

Date
2023
Data type
Media
Theme
Education and outreach
Research and monitoring
Geographic location
Saba
Author

Citizen science and integrative taxonomy reveal a great diversity within Caribbean Chaetopteridae (Annelida), with the description of one new species

Chaetopteridae forms a monophyletic clade showing an uncertain position within Annelida. The family has 75 ubiquitous species within four genera that cluster in two well-supported clades (Chaetopterus–Mesochaetopterus and Spiochaetopterus–Phyllochaetopterus) and includes several cryptic species complexes. Based on integrative taxonomy and supported by citizen science, here we describe one new and two unnamed species of Caribbean chaetopterids. Partial sequences from the nuclear 18S rRNA and mitochondrial Cytochrome Oxidase I genes of all known chaetopterid genera allowed us to (1) discuss the phylogeny of the family and (2) assign the three species into Mesochaetopterus (two) and Phyllochaetopterus (one). Mesochaetopterus stinapa, sp. nov. clearly diverged from all species of the genus, whereas Mesochaetopterus aff. xerecus forms a separate clade with Mesochaetopterus rogeri (Europe) and Mesochaetopterus xerecus (Brazil). Phyllochaetopterus aff. verrilli forms a separate clade with Phyllochaetopterus arabicus (Red Sea) and the closely related sequences from Hawai’i, Australia and French Polynesia attributed to Phyllochaetopterus verrilli (or cf. verrilli). Despite observing differences in morphology (e.g. palp colour pattern, presence or absence of eyespots, chaetal morphology and arrangement) and biogeographical distributions, only the erection of M. stinapa as a new species is well supported by the genetic distance, barcoding gap and species discrimination analyses. Our results emphasise the existence of cryptic species complexes within Mesochaetopterus and Phyllochaetopterus, whose taxonomy will require further morphological, biogeographical and molecular data to be resolved.

 

Request full text here: https://www.publish.csiro.au/IS/IS21081

Correspondence to: dani@ceab.csic.es

Date
2022
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Bonaire

Genetic evidence supports larval retention in the Western Caribbean for an invertebrate with high dispersal capability (Ophiothrix suensonii: Echinodermata, Ophiuroidea)

Abstract The brittle star Ophiothrix suensonii is a com- mon coral reef sponge commensal with high dispersal potential. Here, we utilize COI sequence data from 264 O. suensonii individuals collected from 10 locations through- out Florida and the Caribbean to investigate dispersal dynamics and demographic history. Locations separated by up to 1,700 km lacked genetic differentiation, confirming the ability for long-range dispersal. However, significant differentiation was detected among other regions. Samples from Utila, Honduras showed the greatest differentiation, suggesting that the circulation of the Mesoamerican gyre could be a significant factor restricting gene flow in this region. Demographic analyses provided strong evidence for a population expansion, possibly out of Florida, through the Caribbean, and into Honduras, which commenced in the early Pleistocene. However, the presence of a clade of rare haplotypes, which split much earlier (mid-Pliocene), indi- cates that O. suensonii persisted long before its recent expansion, suggesting a cyclic history of population con- traction and expansion. Finally, patterns of gene flow are not concordant with contemporary surface currents; rather, they reflect historical movements possibly linked with changes in circulation during periods of Pleistocene climate change. 

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