Silk remarkable mechanical properties, comparative biocompatibility, tunable degradation rates "in vitro" and "in vivo", the ease to load cellular growth factors (for example, BMP-2), and the ability to be processed into several other formats such as films, gels, particles, and scaffolds. Silks from "Bombyx mori", a kind of cultivated silkworm, are the most widely investigated silks. Silks derived from "Bombyx mori" are generally made of two parts: the silk fibroin fiber which contains a light chain of 25kDa and a heavy chain of 350kDa (or 390kDa) linked by a single disulfide bond and a glue-like protein, sericin, comprising 25 to 30
Crustacean larva (lecithotrophy). In species with normal development, eggs are roughly 1% of the size of the adult; in species with abbreviated development, and therefore more yolk in the eggs, the eggs may reach 1/9 of the adult's size. The post-larva of shrimp is called "parva", after the species "Acanthephyra parva" described by Henri Coutière, but which was later recognised as the larva of "Acanthephyra purpurea". In the marine lobsters, there are three larval stages, all similar in appearance. Freshwater crayfish embryos differ from those of other crustaceans in having 40 ectoteloblast cells, rather than around 19. The larvae show abbreviated development,