Commemorating Horseshoe Crab Day, Department of MSP IPB University Holds International Symposium
Recent studies on the distribution and population of Horseshoe Crab are in the spotlight among academics. For this reason, in commemoration of Horseshoe Crab Day (June 20) established by The International Union for Conservation of Nature (IUCN), the Department of Aquatic Resources Management (MSP) of the Faculty of Fisheries and Marine Sciences (FPIK) IPB University held an International Symposium, (19 / 6).
In this symposium, there were expert horseshoe crabs from various countries. Among them, Dr. Akbar John from International University Malaysia, Dr. Qian Tang from National University of Singapore, Dr. Jay Ming-Che Yang from Academia Sinica Taiwan, Prof. Hui Ho Lam Jerome from The Chinese University of Hong Kong, Naila Khuril Aini SPi, MSi, IPB University doctoral student, Dr. Gobinda Chandra Biswal from Siddheswar College India and Prof. Dr. Yusli Wardiatno, IPB University lecturer who is a Professor of the MSP Department as the Symposium Chairman.
Head of the MSP Department of IPB University, Dr. Majariana Krisanti in his remarks said, “At this moment I want to express important things for all of us with regard to the mandate based on the declaration in Guangxi, China last year. Where I hope to remind all of us to continue to be enthusiastic in the effort to maintain Horseshoe Crabs around the world. ”
On this occasion, Dr. Akbar John explained that the distribution and population of the Horseshoe Crab decreased from 2010-2020 due to high market demand. Most of the population is only centered in the eastern part of Malaysia, including three species, namely Tachypleus tridentatus, T. gigas, and C. rotundicauda.
“The studies conducted on these species are also mostly about population dynamics and their abundance. The research obstacle experienced by Malaysian researchers is funding and the difficulty of finding standard methods that can determine the exact population in the wild. The Malacca reclamation project and the absence of legal protection are increasingly pressing the population numbers of these crabs, “he said.
While Dr. Qian Tang discusses the relationship between the population of two species of Horseshoe Crab in Singapore with the Holocene Sea Level. He took 300 individual samples from all regions of Singapore and used spatial autocorrelation and resistance mapping methods to determine their dispersal capabilities and calculate heterozygosity and effective population sizes to determine their genetic diversity. Dr. Qian found that the population of C. rotundicauda species declined when sea level rise occurred. Whereas in T. gigas species, on the other hand, although it still depends on habitat dynamics and human disturbance.
Dr Jay Ming-Che Yang discusses the conservation connectivity of the Horseshoe Crab in the Asian region. According to his research, the excessive harvest of these crabs for medical and food needs as well as development along the coast of the crab habitat contributed greatly to the decline in population. It also decreases genetic diversity so that the genetic connectivity of several Horseshoe Crab species in populations that are isolated due to human activity. The way to overcome this is to do community-based conservation and reduce marine waste.
“If we don’t immediately trace the initial DNA database of the crab, the genetic diversity will continue to decline and cause local extinction. For example in the west coast of Taiwan. However, the z-survey method that I did in 2019 rediscovered 13 young crabs, “he explained.Prof. Hui Ho Lam Jerome discusses the origin or ancestor and genomic population of three species of Horseshoe Crab in the mangrove area through eDNA detection. The analysis involved family genes, microRNA, and the syntax of the crab.
While Naila Khuril Aini discusses the morphological evaluation and genetic variation of Horseshoe Crabs by taking samples from the three species of Horseshoe Crabs with the largest number in Java, namely T. gigas, T. tridentatus and C. rotundicauda. The results of his research found that in 2018 and 2019, the morphological features found in T. tridentatus changed, from a spine of three or one to one and the number of populations found decreases.
“The number of small vertebrae in ophistoma can be used as an identification key in order to avoid the hunt for horseshoe crabs that are vulnerable to extinction. The result of genetic variation found in interpopulation is high whereas in medium intrapopulation. “The genetic distance between T. and C. rotundicauda species in the Demak and Madura regions is even closer than in the Balikpapan area,” he said.
Dr. Gobinda Chandra Biswal discusses the abnormalities of the Horseshoe Crab in India. Generally this abnormality is characterized by changes in the exoskeletal of the crab which can be caused by injury, predation, mating or genetic activities. His research took samples of the crab carapace from the Kankadapal area to the east coast of Odisha. Dr. Gobinda found that most of the abnormalities were in the form of telson which turned into crooked or prosomal deformity. Embryonic abnormalities can also occur due to high levels of heavy metals. The exact cause of the abnormality can not be determined. (IAAS / NAS)
Published Date : 19-Jun-2020
Resource Person : Dr Akbar John
Keyword : Horseshoe Crab, Water Resources Management Department, IPB University, IPB lecturer