invertebrates

1. BackgroundInvertebrates play a critica

l role in maintaining a resilient and healthy environment. These speciesare one of the most globally abundant and diverse animal groups, comprising nearly 80% of alldocumented species to date (Brusca &Brusca, 2002). In fact, these species occupy a wide range oftropic levels, interacting with species throughout the food web.One study (Prather et al, 2020) broke down the importance of invertebrates into the following fourecosystem services:

1) Supporting services. This includes primary production, decomposition, nutrient cycling,hydrologic flux and habitat formation and modification. Within the sediment, invertebratescan dramatically influence water movement, increasing soil porosity (Derouard etal., 1997)and decreasing litter quantity (Wardle, 2002).

2) Providing services. These contributions include serving as a food source, or generatinghousehold goods, inclusion in biochemical or pharmaceutical products as well as a boundlesssupply ofscientific study. For Lac, thequeen conch is an iconic species, whose meat washistoricallyfeatured in local cuisine and shellis still usedas decoration.

3) Regulating services. This includes ability to improve water quality, food web stability,disease regulation within populations as well as pest and invader control. In shallow marineecosystems, bivalves (such as mussels and oysters) can provide substantial water filtrationthroughout the water column.

4) Cultural services. This includes benefits obtained from recreational services and theircultural significance. Many iconic invertebrate species, such as octopus, corals, sponges andconch create a vibrant landscape for scuba divers and snorkelers alike to explore.

Lac Bay has great economic,environmental and cultural value, none of which would be possiblewithout a healthy and robust invertebrate population. These invertebrates are help build resiliencewithin the sandy plateaus, seagrass beds and mangroves, serve as a point of interest forvisitors, andareeither themselves iconic, or vital to the success of other iconic species (such as the flamingo andsea turtle)within the bay.

Nederlands below

Two recently published studies document 35 new beetle species for the islands of Saba and St. Eustatius.  Even with these latest additions, it is still estimated that nearly three quarters of the beetle population is still unknown.  Beetles play a vital role in breaking down natural waste and keeping insects in check, both important roles especially for small Caribbean islands.

The lady beetle Cycloneda sanguinea. Credit: Jan-Joost Mekkes

Beetles represent some of the tiniest inhabitants of the Dutch Caribbean but play a critical role in the environment.  They work as tiny decomposers and are vital in recycling nutrients from dead leaves and natural waste back into the ground.  As predators, they can help keep insect populations in check, especially pests like caterpillars and aphids which can damage crops.  Furthermore, with over 350,000 species worldwide, beetles represent a fifth of all living organisms in the world and nearly 40% of described insects.

Taxonomic Impediment

Unfortunately, there is still a lot that researchers don’t know about the beetle populations of the northern Leeward Islands.  Dubbed the “taxonomic impediment”, this is due to the gap between the local taxonomic knowledge and a shortage of trained taxonomists in the region.  In fact, it is estimated that only about 10-20% of the known beetle species of the islands have been correctly identified to date.

New Records

The firefly Aspisoma ignitum, Boven National Park, St. Eustatius. Credit: Jan-Joost Mekkes

Two new studies worked to bridge this gap for the islands of Saba and St. Eustatius.  Between 2008 and 2020, three researchers visited Saba and recorded a total of 22 different beetle species.  Of these, 14 were new to Saba or confirmed previously provisional records and four were new to the Dutch Antilles.  With this new study, the total number of beetle species recorded on Saba is now around 100.

In 2020, one researcher on St. Eustatius was able to collect 46 beetle species, of which 21 were new to the island, including 15 which were new to the Dutch Antilles.  Adding to previous records, this now brings the total number of known beetle species for the island to 117, which researchers believe to be about a quarter of the number of species expected.

The weevil Trichobaris bridwelli, Oranjestad, St. Eustatius. Credit: Jan-Joost Mekkes

Report your sightings

Have you observed any beetles or other insects?

Currently, researcher Jan-Joost Mekkes (jayjaymekkes@hotmail.com) is on Sint Eustatius and Michiel Boeken (michiel.boeken@gmail.com) on Saba.  Please forward them your beetle and other insect sightings.

Or submit your sightings and photos directly yourself on the website www.Observation.org or download the free apps (iPhone (iObs) & Android (ObsMapp)).

Species reports by local communities and tourists are invaluable for nature conservation efforts to help increase public awareness and overall species protection. Besides, DCNA, Observation International and Naturalis Biodiversity Center are working together to develop on automated species identification app for your phone. Your uploaded photos are of great value to make this possible. For questions, please contact research@DCNAnature.org

Read more

You can find the completed list of the beetle species documented during these studies in the Dutch Caribbean Biodiversity Database.

https://www.dcbd.nl/document/results-entomological-collecting-trip-st-eustatius-coleoptera

https://www.dcbd.nl/document/two-small-beetle-collections-saba-coleoptera

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Nieuwe kevers ontdekt in het Nederlands Caribische gebied

Twee recent gepubliceerde studies documenteren 35 nieuwe keversoorten voor de eilanden Saba en St. Eustatius. Ondanks deze laatste toevoegingen wordt geschat dat nog bijna driekwart van de keverpopulatie onbekend is. Kevers spelen een cruciale rol bij het afbreken van natuurlijk afval en het onder controle houden van insecten, beide belangrijk voor de Caribische eilanden.

Het lieveheersbeestje Cycloneda sanguinea, F.D. Roosevelt Airport, St. Eustatius. Credit: Jan-Joost Mekkes

Kevers zijn een van de kleinste bewoners van het Nederlands Caribisch gebied maar spelen een cruciale rol in de natuur. Ze werken als kleine ontbinders en zijn van vitaal belang bij het recyclen van voedingsstoffen uit dode bladeren en brengen natuurlijk afval terug in de grond. Als roofdieren kunnen ze helpen insectenpopulaties onder controle te houden, met name plagen zoals rupsen en bladluizen die gewassen kunnen beschadigen. Bovendien vertegenwoordigen kevers, met meer dan 350.000 soorten wereldwijd, een vijfde van alle levende organismen in de wereld en bijna 40% van de beschreven insecten.

Taxonomische belemmering

De vuurvlieg Aspisoma ignitum, Boven National Park, St. Eustatius/ Credit: Jan-Joost Mekkes

Helaas is er nog veel dat onderzoekers niet weten over de keverpopulaties van de noordelijke Caribische eilanden. Ook wel de “taxonomische belemmering” genoemd. Dit komt door de kloof tussen de lokale taxonomische kennis en een tekort aan opgeleide taxonomen in de regio. Er wordt zelfs geschat dat tot op heden slechts ongeveer 10-20% van de bekende keversoorten van de eilanden correct zijn geïdentificeerd.

Nieuwe waarnemingen

De snuitkever Trichobaris bridwelli, Oranjestad, St. Eustatius. Photo credit: Jan-Joost Mekkes

Twee nieuwe studies hebben deze kloof voor de eilanden Saba en Sint Eustatius overbrugd. Tussen 2008 en 2020 bezochten drie onderzoekers Saba en registreerden in totaal 22 verschillende keversoorten. Hiervan waren er 14 nieuw op Saba of bevestigde eerdere voorlopige waarnemingen en vier waren nieuw voor het Caribisch deel van het Koninkrijk der Nederlanden. Met deze nieuwe studie ligt het totale aantal geregistreerde keversoorten op Saba nu rond de 100.

Een onderzoeker op Sint Eustatius heeft in 2020 46 keversoorten kunnen verzamelen, waarvan 21 nieuw voor het eiland, waarvan 15 nieuw voor het Caribisch deel van het Koninkrijk der Nederlanden. Toegevoegd aan eerdere records, brengt dit nu het totale aantal bekende keversoorten voor het eiland op 117, wat volgens onderzoekers ongeveer een kwart is van het verwachte aantal soorten.

Rapporteer uw waarnemingen

Heb je kevers of andere insecten waargenomen?

Momenteel zit onderzoeker Jan-Joost Mekkes (jayjaymekkes@hotmail.com) op Sint Eustatius en Michiel Boeken (michiel.boeken@gmail.com) op Saba. Ze ontvangen graag uw kever- en andere insectenwaarnemingen.

Of upload uw waarnemingen en foto’s direct zelf in op de website www.Observation.org of download de gratis apps (iPhone (iObs) & Android (ObsMapp)).

Soortenrapporten door lokale gemeenschappen en toeristen zijn van onschatbare waarde voor inspanningen op het gebied van natuurbehoud om het publieke bewustzijn en de algemene bescherming van soorten te vergroten. Daarnaast werken de Dutch Caribbean Nature Alliance (DCNA), Observation International en Naturalis Biodiversity Center samen aan de ontwikkeling van een geautomatiseerde app voor het identificeren van soorten voor je telefoon. Uw geüploade foto’s zijn van grote waarde om dit mogelijk te maken. Neem voor vragen contact op met research@DCNAnature.org

Lees meer

De volledige lijst van de tijdens deze onderzoeken gedocumenteerde keversoorten vindt u in de Dutch Caribbean Biodiversity Database.

https://www.dcbd.nl/document/results-entomological-collecting-trip-st-eustatius-coleoptera

https://www.dcbd.nl/document/two-small-beetle-collections-saba-coleoptera

Published in BioNews 51 

Abstract

Sponges are a diverse phylum of sessile filter-feeding invertebrates that are abundant on Caribbean reefs and provide essential ecological services, including nutrient cycling, reef stabilization, habitat, and food for a variety of fishes and invertebrates. As prominent members of the benthic community, and thus potential food resources, factors determining the biochemical and energetic content of sponges will affect their trophic contributions to coral reef ecosystems. In order to evaluate the influence of geographic variation on biochemical composition and energetic content in the tissue of sponges, we collected several common and widespread species (Agelas conifera, Agelas tubulata, Amphimedon compressa, Aplysina cauliformis, Niphates amorpha, Niphates erecta, and Xestospongia muta) from multiple shallow reefs in four countries across the Caribbean Basin, including Belize, Curaçao, Grand Cayman, and St. Croix, U.S. Virgin Islands. In addition, we correlated inherent species-level traits, including the production of antipredator chemical defenses and the relative abundance of microbial symbionts, with biochemical and energetic content. We found that energetic content was higher in sponges with antipredator chemical defenses, and was significantly correlated with the concentration of chemical extracts from these sponges. We also noted that sponges with high microbial abundance contained significantly more soluble protein than sponges with low microbial abundance. Finally, both biochemical and energetic content varied significantly among sponges from different locations; sponges from Grand Cayman had the highest lipid and energetic content, whereas sponges from Belize had the highest carbohydrate content but lowest energetic content. Despite similar environmental conditions at these sites, our results demonstrate that biochemical and energetic content of sponges exhibits geographic variability, with potential implications for the trophic ecology of sponges throughout the Caribbean Basin.

https://doi.org/10.1111/ivb.12341