The so-called arctus or bear-crab lays its eggs at about the
same time as the crawfish; and consequently in winter and in the
spring-time, before laying their eggs, they are at their best, and
after laying at their worst.

They cast their shell in the spring-time (just as serpents
shed their so-called 'old-age' or slough), both directly after birth
and in later life; this is true both of crabs and crawfish. And, by
the way, all crawfish are long lived.