Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia.
Shantou University-Universiti Malaysia Terengganu (STU-UMT) Joint Shellfish Research Laboratory, Shantou University, Shantou, Guangdong, China.
PeerJ. 2022 Aug 23;10:e13961. doi: 10.7717/peerj.13961. eCollection 2022.
Mud crabs (genus ) are gaining attention as potential aquaculture species due to their lucrative market price and high demand. One of the essential components of mud crab culture is broodstock quality. The optimisation of mud crab broodstock culture currently focused on its nutritional aspects and common rearing parameters, including stocking density and temperature. The use of sandy substrate to induce egg extrusion in female broodstock is common; however, its optimisation has never been conducted. This study investigated (1) the substrate association of two species (, ) during broodstock conditioning until egg extrusion when the choices of fine (66.99 ± 14.48 μm) and coarse (656.17 ± 38.13 μm) sands were given; (2) the female reproductive output when females were individually exposed to either fine sand, coarse sand, or no sand treatments. Females, spawners and non-spawners, of and were associated with fine sand and none was observed to bury in the coarse sand tray. The occurrence of egg extrusion was not significantly different between species but moderately associated with the duration of visits (stayed in sand for 1 d, 2 d, ≥3 d). The final incubation period in the sand tray was more than 2 days in all cases, except for one female (buried in the sand for 1 day prior to egg extrusion). When no choice was available, the highest percentage (58.3%) of females extruded eggs in fine sand treatment, followed by coarse sand treatment (33.3%), and no sand treatment (8.3%). Sand type influenced the weight of egg clutch, total egg number, fecundity, and clutch size. These results suggest that fine sand (<70 μm) substrate should be incorporated into broodstock rearing to maximise female reproductive output.
泥蟹（属）因其高市场价格和高需求而成为有前途的水产养殖物种，引起了人们的关注。泥蟹养殖的一个重要组成部分是亲蟹质量。目前，泥蟹亲蟹养殖的优化主要集中在其营养方面和常见的养殖参数上，包括放养密度和温度。在雌性亲蟹中使用沙质基质来诱导卵子排出是很常见的；然而，其优化从未进行过。本研究调查了（1）在卵子排出之前，两种泥蟹（、）在亲蟹培育期间对细沙（66.99±14.48μm）和粗沙（656.17±38.13μm）的选择的基质关联；（2）当 只雌蟹分别暴露于细沙、粗沙或无沙处理时的雌性生殖输出。和 的产卵亲蟹和非产卵亲蟹都与细沙有关，而没有观察到有亲蟹钻入粗沙盘。卵子排出的发生在两种物种之间没有显著差异，但与访问时间（在沙中停留 1 天、2 天、≥3 天）中度相关。在所有情况下，最终的孵化期都超过了 2 天，除了一只 （在卵子排出前一天埋在沙子里 1 天）。当没有选择时，有 58.3%的雌蟹在细沙处理中排出卵子，其次是粗沙处理（33.3%），无沙处理（8.3%）。沙质类型影响卵 clutch 的重量、总卵数、繁殖力和 clutch 大小。这些结果表明，应将小于 70μm 的细沙基质纳入 亲蟹养殖中，以最大限度地提高雌性生殖输出。
