Oxygen consumption in trilobite larvae of the mangrove horseshoe crab (Carcinoscorpius rotundicauda; Latreille, 1802): effect of temperature, salinity, pH, and light–dark cycle

Abstract

Carcinoscorpius rotundicauda is one of the four extant species of horseshoe crab, occurring only in Asia: around India, Indonesia, Malaysia, Philippines, Singapore, Thailand and Hong Kong. Virtually nothing is known about the physiology of this Asian species. In the present study, the respiratory physiology in terms of oxygen consumption rate of the trilobite larvae of C. rotundicauda was evaluated under laboratory conditions. The trilobite larvae were exposed to different levels of temperature (10, 20, 30 and 40 °C), salinity (10, 20, 30 and 40 ppt), pH (5, 6, 7, 8 and 9) and dark-light conditions for a period of 12 h. Effect of temperature on oxygen consumption in trilobite larvae was not so significant among all the temperatures tested. However, both 10 and 40 °C temperature showed comparatively high rate of oxygen consumption at the initial 4 h of experiment. More or less consistent oxygen consumption pattern observed at 20 and 30 °C temperature suggested 20-30 °C as the best temperature range for rearing trilobite larvae. Trilobite larvae revealed enormous tolerance to temperature and indicated that the temperature is not critical in terms of respiration. The trend in oxygen consumption was more or less uniform at all salinities tested indicating the insignificant influence of salinity on respiration. Though not significant, the oxygen consumption trend was more consistent at 20 ppt as compared to other salinities and thus could be considered as the most suitable salinity for rearing trilobite larvae. There was a positive relationship between oxygen consumption rate and the

Characteristics and density of the horseshoe crab (Tachypleus gigas) from gillnet fishery in Pamekasan, Madura Island

“…The water depth is 5±0; a good depth for horseshoe crab growth is 1.6 m [15]. The water quality parameter values needed by horseshoe crabs for growth include salinity of 27-37 [18], pH of 7-9 [19], current velocity, and strong waves that are not suitable for the spawning process [20]. According to [12], the composition of the type of sediment fraction and the chemical quality of the sediment in Polagan waters that support horseshoe crab growth is 57.36% sand and 65.47% mud, with sandy sediments accounting for 83.14±27.72% and silt 16.84±27.70%.…”

POPULATION STRUCTURE AND MORPHOMETRY OF HORSESHOE CRAB Carcinoscorpius rotundicauda, Latreille 1802 IN KAMPUNG GISI COASTAL AREA OF BINTAN BAY OF RIAU ISLANDS PROVINCE

“…Disamping kondisi mangrove dan substrat di stasiun 3 yang mendukung keberadaan belangkas berukuran besar, juga kadar salinitas yang rendah di stasiun ini berpengaruh terhadap laju metabolisme yang cenderung meningkatkan laju pertumbuhannya (Mantel and Farmer, 1983;Srijaya et al, 2014). Dengan demikian, kerapatan mangrove yang tinggi, substrat berlumpur, dan salinitas yang rendah berkontribusi terhadap pertumbuhan belangkas, karena menyediakan makanan dan kenyamanan bagi kehidupan belangkas.…”