RP-Department of Zoological Sciences

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Browsing RP-Department of Zoological Sciences by Subject "Acropora"

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    Community-Managed Coral Reef Restoration in Southern Kenya Initiates Reef Recovery Using Various Artificial Reef Designs
    (Frontiers in Marine Science, 2023-04) Knoester, EG.; Rienstra, JJ.; Schürmann, QJF.; Wolma, AE.; Murk, AJ.; Osinga, R.
    Monitoring of reef restoration efforts and artificial reefs (ARs) has typically been limited to coral fragment survival, hampering evaluation of broader objectives such as ecosystem recovery. This study aimed to determine to what extent AR design influences the ecological recovery of restored reefs by monitoring outplanted coral fragments, benthic cover, coral recruitment and fish and invertebrate communities for two years. Four AR designs (16 m2 ), unrestored controls and natural reef patches as reference (n = 10) were established in Mkwiro, Kenya. ARs consisted either of concrete disks with bottles, layered concrete disks, metal cages or a combination thereof. A mixture of 18 branching coral species (mainly Acropora spp.) was outplanted on ARs at a density of 7 corals m-2. After two years, 60% of all outplanted fragments had survived, already resulting in coral cover on most ARs comparable (though Acropora-dominated) to reference patches. Coral survival differed between ARs, with highest survival on cages due to the absence of crown-of-thorns sea star predation on this design. In total, 32 coral genera recruited on ARs and recruit densities were highest on reference patches, moderate on concrete ARs and low on cages. ARs and reference patches featured nearly twice the fish species richness and around an order of magnitude higher fish abundance and biomass compared to control patches. Fish abundance and biomass strongly correlated with coral cover on ARs. AR, reference and control patches all had distinct fish species compositions, but AR and reference patches were similar in terms of trophic structure of their fish communities. Motile invertebrates including gastropods, sea urchins, sea cucumbers and sea stars were present at ARs, but generally more abundant and diverse at natural reference patches. Taken together, all studied ecological parameters progressed towards reef ecosystem recovery, with varying influences of AR design and material. We recommend a combination of metal cages and layered concrete ARs to promote high fragment survival as well as natural coral recruitment. Ultimately, a longer period of monitoring is needed to fully determine the effectiveness reef restoration as conservation tool to support coral reef ecosystem recovery
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    DNA Barcoding, Dwelling Morphology, and Fecundity of the Gall-Forming Shrimp Paratypton Siebenrocki Balss, 1914 (Caridea: Palaemonidae)
    (Tylor and Francis, 2023) van der Meij, Sancia E. T.; Bouwmeester, Jessica; Bähr, Susanne
    Tropical coral reefs offer a wide variety of habitats to countless invertebrate species. Sessile host organisms especially are inhabited by small taxa, of which decapod crustaceans form one of the most diverse communities. Symbiotic palaemonid shrimp species associate with marine invertebrate hosts from multiple phyla, including cnidarians such as stony corals (Scleractinia). The intriguing gallforming shrimp Paratypton siebenrocki, a symbiont of Acropora corals in the Indo-Pacific, was collected in the Saudi Arabian Red Sea, Kenya, and the Maldives. Based on morphology P. siebenrocki has been considered to be most closely related to the genera Anapontonia and Metapontonia; however, no clear clustering with either palaemonid genus was observed in a phylogenetic reconstruction based on 16S and COI mtDNA. Here we photo-document the dwellings of P. siebenrocki in Acropora spp. for the first time, and furthermore we report on the reproductive output of this species. The number of eggs ranged from 345 to 909 (n = 6), and embryo volume differed strongly between early- and late-stage embryos. The carapace length ranged from 2.58 to 4.55 mm for the females and 1.51 to 2.5 mm for the males (n = 5). The number and size of the embryos, combined with their specialised, secluded lifestyle, suggest that P. siebenrocki allocates higher energy towards embryo production than free-living confamilials do.