Embryonic development and fecundity of the red deep-sea crab Chaceon quinquedens Smith, 1879) (Decapoda: Brachyura: Geryonidae) in the Mid-Atlantic Bight determined by image analysis

摘要

The red deep-sea crab, Chaceon quinquedens (Smith, 1879), has been harvested from the US Atlantic continental shelf since the 1970s, but knowledge about its biology is extremely limited. We describe the stages and seasonality of embryonic development and determine size-specific fecundity for C. quinquedens in the Mid-Atlantic Bight. Samples were collected by trawling aboard research vessels in 2012-2013, and from traps aboard commercial fishing vessels in 2014-2016. Four stages of embryonic development were described: 1) early development, 2) mid-development, 3) late development, and 4) hatching. A relationship between embryonic development stage and egg-mass color was observed. A brooding cycle was proposed after analyzing seasonal changes in the stages of embryonic development. Fecundity was estimated by using an automated imaging method for egg samples during stage 1 and 2. The estimates of fecundity, the number of eggs per brood, ranged from 34,691 to 324,729 for females between 62.6 and 106.2 mm in carapace length (CL). The linear regression showed a positive correlation between fecundity and female body size in CL (R-2 = 0.56). This study provides information on reproductive parameters needed to improve fisheries management.