ABSTRACT
Environmental DNA (eDNA) metabarcoding has the potential to revolutionize conservation planning by providing spatially and taxonomically comprehensive data on biodiversity and ecosystem conditions, but its utility to inform the design of protected areas remains untested. Here, we quantify whether and how identifying conservation priority areas within coral reef ecosystems differs when biodiversity information is collected via eDNA analyses or traditional visual census records. We focus on 147 coral reefs in Indonesia's hyper-diverse Wallacea region and show large discrepancies in the allocation and spatial design of conservation priority areas when coral reef species were surveyed with underwater visual techniques (fishes, corals, and algae) or eDNA metabarcoding (eukaryotes and metazoans). Specifically, incidental protection occurred for 55% of eDNA species when targets were set for species detected by visual surveys and 71% vice versa. This finding is supported by generally low overlap in detection between visual census and eDNA methods at species level, with more overlap at higher taxonomic ranks. Incomplete taxonomic reference databases for the highly diverse Wallacea reefs, and the complementary detection of species by the two methods, underscore the current need to combine different biodiversity data sources to maximize species representation in conservation planning.
Subject(s)
Anthozoa , DNA, Environmental , Animals , Coral Reefs , Ecosystem , DNA, Environmental/genetics , Biodiversity , Anthozoa/genetics , Fishes , DNA Barcoding, TaxonomicABSTRACT
Insular biodiversity hotspots of Southeast Asia are remarkable for their biodiverse faunas. With a marine larval phase lasting up to several months, the freshwater fish subfamily Sicydiinae has colonized most islands of these hotspots. However, Sicydiinae diversity is still poorly understood in Southeast Asia. With the objective to estimate intraspecific genetic diversity and infer past demography, we conducted the molecular inventory of Sicydiinae species in Sundaland and Wallacea using 652 bp of the mitochondrial cytochrome oxidase I gene, species delimitation methods and Bayesian Skyline plot reconstructions. In total, 24 Molecular Operational Taxonomic Units are delimited among the 603 sequences belonging to 27 species and five genera. Two cases of discordance between morphology and mitochondrial sequence are observed suggesting ongoing speciation and/or introgression in two genera. Multiple new occurrences are reported, either for a single biodiversity hotspot or both, some of which corresponding to observations of a few individuals far from the range distribution of their conspecifics. Among the ten species or species group whose intraspecific diversity was examined, high levels of genetic diversity and past population expansion are revealed by Tajima's D tests and Bayesian Skyline Plot reconstructions. Together these results indicate that long-distance dispersal is common and suggest that most endemic species originated through founder events followed by population expansion. Patterns of sexual dimorphism and males' coloration among diverging species pair seem to point to sexual selection as an important mechanism contributing to speciation in the Sicydiinae of Sundaland and Wallacea.
ABSTRACT
A size-based, histological analysis of the reproductive life history of the blacktip grouper, Epinephelus fasciatus (Forsskål 1775), was conducted in Indonesia to evaluate the error rate associated with macroscopic reproductive analysis. Histological results indicated that E. fasciatus was protogynous with female L50 at 13.4 cm total length (LT) and a size at sexual transition of 22.0 cm LT. The weight-length relationship for the species was W = 0.011 L3.13. Overall sex ratios were significantly female biased, operational sex ratios were significantly male biased, and sex ratios of mature individuals varied predictably with length from female to male dominance as size increased. No significant relationship between length and batch fecundity was found. The population has a spawning period from February to August. Overall, 54.4% of macroscopic evaluations were incorrect compared to histological results. Of the errors, 14.8% were a failure to detect ovotestes, 12.7% were classifying non-gonadal tissue as ovary or testis, 12.2% were misclassifying sex, and 12.7% were misclassifying maturity status. However, the largest source of error (47.7%) was from misclassifying both sex and maturity status. Of these, 92.9% were macroscopically classified as immature females, but were histologically confirmed to be mature males. Compared to histological results, the only accurate macroscopic results were the absence of a sex-based difference in weight-length relationship and spawning seasonality estimated by a gonadosomatic index (February-June). The use of macroscopic methods to estimate reproductive life-history parameters for sex-changing reefes fish may introduce significant inaccuracies and misinterpretations. Of the parameters estimated by histological methods, size at maturity, size-specific sex ratios, and spawning seasonality have the greatest potential to inform local fishery management policy.
ABSTRACT
Fluorescence is a widespread phenomenon found in animals, bacteria, fungi, and plants. In marine environments fluorescence has been proposed to play a role in physiological and behavioral responses. Many fluorescent proteins and other molecules have been described in jellyfish, corals, and fish. Here we describe fluorescence in marine species, which we observed and photographed during night dives in the Banda Sea, Indonesia, and in the Red Sea, Egypt. Among various phyla we found fluorescence in sponges, molluscs, tunicates, and fish. Our study extends the knowledge on how many different organisms fluoresce in marine environments. We describe the occurrence of fluorescence in 27 species, in which fluorescence has not been described yet in peer-reviewed literature. It especially extends the knowledge beyond Scleractinia, the so far best described taxon regarding diversity in fluorescent proteins.