Effects of co-supply ratios of swimming crab Portunus trituberculatus zoeae and Artemia on survival and growth of East Asian common octopus Octopus sinensis paralarvae under an upwelling culture system

Abstract

Despite recent advances in culture technology for East Asian common octopus Octopus sinensis paralarvae using upwelling systems, securing suitable feed for the paralarvae is an unresolved issue. The zoea of the swimming crab Portunus trituberculatus is a good candidate for paralarval feed because of the high fecundity of the adult females. To investigate the effects of supplying P. trituberculatus zoeae and their feeding method on paralarvae, we cultured paralarvae with supplying different combination ratios of zoeae and Artemia (10:0, 7:3, 5:5, 3:7 and 0:10), and with or without supplementing rotifers using small‐scale (3‐L) upwelling systems. Paralarval survival rate and growth were improved when zoeae were supplied as the main feed, but reduced when the proportion of Artemia exceeded half the whole preys. Supplementing rotifers did not affect the paralarval survival and growth. Subsequently, paralarvae were cultured by supplying zoeae (partially augmented by Artemia) using three large (1‐kl) upwelling systems to assess their feeding effectiveness in juvenile octopus production. Paralarvae could be cultured at high survival rates of 77.1 ± 5.1% to reach benthic juveniles at 23 days after hatching. In conclusion, supplying P. trituberculatus zoeae augmented with Artemia under an upwelling culture system has great potential for juvenile octopus production.

Chromosome‐level genome assembly of the East Asian common octopus (Octopus sinensis) using PacBio sequencing and Hi‐C technology

“…Mature O. sinensis individuals have a relatively broader head and shorter arms with fewer suckers than the European O. vulgaris (Gleadall, 2016). Due to its rapid growth and high commercial value, O. sinensis is considered to be a promising candidate for aquaculture; hence, various culture technologies have been studied in China and Japan (Dan et al., 2019; Xu et al., 2019). Currently, massive paralarval mortality, apparently primarily caused by nutritional deficiency, is the main bottleneck to its commercial production (Dan et al., 2019).…”

“…Due to its rapid growth and high commercial value, O. sinensis is considered to be a promising candidate for aquaculture; hence, various culture technologies have been studied in China and Japan (Dan et al., 2019; Xu et al., 2019). Currently, massive paralarval mortality, apparently primarily caused by nutritional deficiency, is the main bottleneck to its commercial production (Dan et al., 2019). Genomic information will enable transcriptome analysis to produce more accurate gene expression profiles, especially for the genes related to metabolic processes, which will provide a better understanding of the nutritional requirements of O. sinensis during its paralarval stage.…”

Stepwise changes in morphology during the settlement process in a merobenthic octopus, Octopus sinensis, raised in the laboratory

“…The WW of the females ranged 0.51-2.37 kg. They were maintained in rearing tanks, according to the method described by Dan et al (2019), and fed ad libitum with live Asian paddle crab, Charybdis japonica; Japanese mitten crab, Eriocheir japonica; Pacific oyster, Crassostrea gigas; or manila clam, Ruditapes philippinarum. After female octopuses started spawning on the ceiling of their shelter, they were maintained without feeding until hatching occurred.…”

“…Settlement occurs in rearing tanks when ML reaches about 7.5 mm (Itami et al, 1963;Villanueva, 1995;Villanueva & Norman, 2008). In recent years, the rearing technology for paralarvae of O. sinensis has largely improved (Dan et al, 2018;Dan et al, 2019;Dan, Takasugi, Iwasaki, Shibasaki, Oka, et al, 2020;Dan, Takasugi, Iwasaki, Shibasaki, Yamashita, et al, 2020), thereby allowing the assessment of the ontogenetic behavioral changes across the paralarval and juvenile phases.…”

Effect of hatching time and starvation on morphometrics and biochemical composition of Octopus tetricus paralarvae

“…Experiments with live Artemia as the sole or main food items have resulted in poor growth and survival, and the benthic phase of paralarval development is usually not reached (e.g. Berger, 2010; Dan et al, 2019; De Wolf et al, 2011; Hamasaki et al, 1991; Navarro & Villanueva, 2003; Roo et al, 2017), with the lack of intake of polyunsaturated fatty acids (PUFA), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), being identified as the likely cause (Hamasaki & Takeuchi, 2001; Iglesias & Fuentes, 2014; Iglesias et al, 2007; Navarro et al, 2014; Navarro & Villanueva, 2000, 2003; Uriarte et al, 2011).…”