EGG-I>AYL\G OF CRAYFISH 



E. A. ANDREWS 



Tx crayfish, as in related Crustacea, the e^^gs are carried fastened 

 to the limbs of the abdomen during the long period of develop- 

 ment that precedes their hatching. As the openings of the ovi- 

 ducts arc upon the thorax, the eggs have to be transported some 

 distance to reach the abdominal limbs. It is the purpose of this 

 article to describe some of the activities of the female associated 

 with the extrusion of eggs from the oviducts, then- trans])ortation 

 to the limbs of the abdomen, and their fixation there. 



In a crayfish in France, a species of Astacus, some of the behav- 

 ior of the female in laying was long since made out by Chantran 

 {Com'pt Rend. Acad. Sci. Paris, vol. 71, pp. 43-i:), 1S70; vol. 74, 

 pp. 201-202, 1872) in his long continued and careful study of the 

 life history of the crayfish. His too l)rief statements are as follows. 

 The female crayfish stands up and for se\eral hour, .ecretc. a 

 viscid mucus from the limbs of the Mnmvu. ll tli.Mi lir. ,!.,wn 

 upon its back ^^ith the ahdonu-n l.rnt toiu.n.l tnu.u.l th.^ ..pm- 

 ings of the oviducts, in such a way as to fonii n sort <.l" . lianil.cr. 

 in ^^hich, on the following night, "the c^^. xnciv tr.u^rd a> they 

 were expelled from the reproductive oii:;iiis. in dithicut bMiiales 

 the expulsion of eggs lasted from one to sevcinl hours. The 

 eggs were plunged into the nuicu^ ^^huh, .is i, ^^vvv, bound the 

 edges and iUv end .)f the abdomen to the tliorax and also helped 

 to make the boundary of the above mentioiinl chamber or basket. 

 In this chandn-r then- ^^a^ s,>nu' uater as as c-- and mucus. 

 All the eggs wen- laid at one pvvlod and rarely were any laid in 

 the day time. 



Observations upon the hivinu' habits of an American crayfish, 

 Cambarus ajjinis, a< publislied' in this journal ^Amn: Xai., vol. 



acco'mr. Ke.iewr-d ob>ervation> iip.u. th.- same species in April, 

 1904, have added more (k>taiis and verified supi>ositioi.s previously 



transport of eggs. 



