The existence of horseshoe crabs Tachypleus gigas is currently on the threatened condition and its population status is also unclear. The objectives of this research were to asses the horseshoe crabs morphological characters and to identify based on molecular marker of Cytochrome Oxydase Subunit I (COI) gene. The samples were collected from five locations (Segara Menyan Subang, Ujung Kulon Banten, Tambak Lorok Semarang, Betah Walang Demak, and Kenjeran Surabaya) in October 2014 until June 2015. A total of 27 parameters for 62 individuals were used to determine connectivity and character identifier among populations. Data were tested using non-parametric analysis. While, the 5 individuals from each sites were used for molecular analysis including several stages of the DNA extraction, DNA electrophoresis, amplification and visualization of DNA fragments, and DNA sequencing. The results obtained based on morphological characters that T. gigas of Surabaya formed a unique group due to its body size (X1-X2 and X4-X16) was larger than the other 5 body parts (X22, X23, X26-X28) of Semarang, Demak, Subang, and Banten. According to molecular results, there were 650 bp conserve nucleotide sequences. Analysis using software MEGA 5.0 showed that there were 73 existence of specific nucleotide sites that can be used to distinguishes between T. gigas in-groups and out-groups (T. gigas from Central Arabian Sea, T. tridentatus from Sweden, and Carcinoscorpius rotundicauda from USA).Keywords: horseshoe crabs, Java coast, morphology, identification molecular, CO1 gene.
1 December 2022 in Journal of Ecological Engineering
Horseshoe crabs have survived until Holocene but, their persistence beyond the Anthropocene is challenged by drastic environment modifications that entail impoverishments and the resultant unusual growth sizes. Previously, allometry via morphometric ratio was introduced to classify horseshoe...
Nature-based solutions (NbSs) of biodiversity conservation and ecosystem restoration have been paid increasing attention as an essential approach to slow down climate change. However, to what degree an NbS approach will contribute to the combined effects of human intervention and climate change has not been well studied. From a habitat quality perspective, we set four NbS scenarios to analyze whether the NbS—mangrove restoration in particular—will be enough for climate change in Xiamen Bay of Fujian Province, China. The habitat quality module of the InVEST model (InVEST-HQ) and the Sea Level Affecting Marshes Model (SLAMM) were used to simulate the spatial-temporal changes in habitat types and habitat quality. Results show that (1) rising sea levels will cause coastal squeeze effects, impacting habitat quality due to erosion and inundation in the study area; (2) mangrove restoration is an effective way to mitigate climate change effects and to increase habitat quality; and (3) further analysis of the effectiveness of mangrove restoration shows that the consideration of mangrove fragmentation effects and sea-use impacts are necessary. The findings in this study will enrich the international discussion of NbSs to climate change in coastal areas.