In Penghu’s maritime slang, “Pebble crabs in Double Third Festival are so plump that they would break the container” and “Pebbles crabs are plumpest when the octopuses are out,” implying that the period between March to June in the Chinese calendar is when the pebble crabs (Smooth Spooner Crab) are the plumpest and delicious, this period is also the high season for Penghu octopuses. However, it was discovered in recent years that the number of Penghu octopuses is gradually decreasing and although the Penghu County Government has already announced a closed fishing season to prevent the extinction of Penghu octopuses, the number of octopuses still showed no sign of increasing.  One of the reasons analyzed could be that Smooth Spooner Crabs, the staple food for octopuses have been overfished, resulting in the broken food chain.  Therefore, to save Penghu octopuses, the National Academy of Marine Research joined forces with the National Penghu University of Science and Technology, as well as the Penghu Marine Biology Research Center to conduct a series of research on Smooth Spooner Crabs, including data collection and analysis on their distribution in the wild, population, reproduction and ecology…etc. in Penghu; the artificial culturing approach is further utilized for preliminary observation on their feeding habits and also attempted to conduct indoor mating and propagation.  Moreover, attempts will be taken to culture juvenile Smooth Spooner Crabs, to establish the culturing technology step by step, hoping to proceed with mass production in the future and to release them to the Penghu sea area in order to increase the population quantity in the wild.
  The President of NAMR, Chiu Yung-Fang indicated that this program is focused on restoring the food for Penghu octopuses – “Smooth Spooner Crabs”, hoping that via the increase of quantity for the Smooth Spooner Crabs in the wild to guarantee the source of bait for Penghu octopuses. However, the conditions of Penghu’s local Smooth Spooner Crab population should be investigated beforehand, along with the setup of the culturing technology.
  Professor Chih-Yun Shih from the Department of Aquaculture, National Penghu University of Science and Technology mentioned it was discovered from the investigation results that the spawning rate for Smooth Spooner Crabs is huge and if the habitat for Smooth Spooner Crabs can be managed appropriately, it should be able to gradually restore the quantity of the wild population.  Director Heng-Yi Hsieh of Penghu Marine Biology Research Center pointed out that the current indoor mating and propagation techniques are capable of allowing the crabs to proceed with mating and spawning under an artificial environment.  As for the culturing technique, we are currently successfully in culturing to the megalopa stage, where they would transform into juvenile crabs after shelling; however, there are still some bottlenecks that need to be surmounted. In the future, if habitat management and the release to the wild can be conducted in parallel, it will be beneficial to the increase of the Penghu octopus population.
  Smooth Spooner Crab (scientific name: Etisus laevimanus) is commonly known as Pebble Crab, it is categorized as Xanthidae and can be commonly seen to live amongst the coral reefs or gaps between rocks in the tidal zone; it is a frequently seen species in the Penghu tidal zone. Moreover, in order to overcome the drastic environment of the tidal zone (such as changes in dryness, temperature, and salt concentration…etc.), its shell is thicker and heavier, resulting in their slow movement, hence, they are extremely easy to capture.  Due to man-made factors including overfishing or destroyed habitat in recent years, there is a decreasing trend in the population.