This study compares timing of egg extrusion, embryo development, timing and duration of eclosion, and incubation periods of Kodiak, Alaska, primiparous and multiparous Tanner crabs (Chionoecetes bairdi) reared in identical conditions to determine if and how these variables differ between reproductive states. Female reproductive state (primiparous or multiparous) and dates of egg extrusion were recorded, eggs were sampled monthly to determine egg stage and area, and larvae were collected daily during eclosion to determine timing and duration of eclosion. Primiparous Tanner crabs extruded eggs on average 103 days earlier than multiparous females and embryos developed similarly between groups. Both groups exhibited an embryonic developmental diapause at the gastrula stage, but the length of diapause was approximately 6 months for the primiparous group and 3 months for the multiparous group. This diapause appears to synchronize eclosion. The eggs of primiparous Tanner crabs were significantly smaller than the eggs of multiparous females for a few months after extrusion, but the differences may not be biologically significant. Eclosion was relatively synchronous between the two groups, however the mean eclosion date was 10 days earlier for primiparous females and on average, eclosion took 7 days for primiparous females and 12 days for multiparous females. Primiparous Tanner crabs have an average incubation period of 489 days which is 92 days longer than the average multiparous female incubation period of 397 days. Results of this study clearly illustrate that reproductive cycles differ between primiparous and multiparous Tanner crabs which may result in different reproductive potentials. Differences between primiparous and multiparous Tanner crabs must be understood and included in models for effective stock assessment, fishery management plans, and rebuilding plans.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.