She will then migrate to the more saline lower portions of the lower bay, while he remains and seeks another female. The females will molt and the male will then deposit his sperm into a sac called a spermatophore – which he then deposits to the female.
![blue crab eggs blue crab eggs](https://benevolentbowd.ca/wp-content/uploads/2018/06/map-summerset-geysers.jpg)
Fishermen refer to them as “doublers” during this time. Males cradle the females beneath his legs for several days waiting for the right location and moment to breed. Females join them during mating season – which is in late spring and summer. Males are typically found in the lower salinities of the upper bay. They have numerous predators including fish, birds, mammals, and sea turtles.īlue crabs can be found in a variety of salinities (euryhaline). Those enjoy crabbing know this – you can put just about anything as bait in a crab trap and it works. They are active hunters – usually using the ambush method of capture (buried in the sand), but are also known scavengers – eating any bits of food they can find. Those this type of eye does not give as clear an image as ours it is very good at detecting motion and has served the arthropods very well over the years.įor blue crabs, food can be just about anything. The more pixels (lenses) you have, the clearer the image. It is much like the image you see on television when they are trying to block out a brand name, or someone’s face. Rather each lenses provides them with a single pixel of light. Each lens does not provide them with an image of you or me however. Their eyes differ from ours in that they have numerous lenses, compared to our single one, and are called compound eyes. They are very good at burying in the sand – eyes and antenna exposed – and sensory cells all working – seeking prey and avoiding predators. There are other crabs who have these swimming paddles and they are all called protunid crabs.īlue crabs perceive their world through their eyes, antenna, and sensory cells on their body. They can swim forwards, backwards, and laterally – and they are often seen swimming at the surface. Blue crabs differ from other crabs in that their last pair of legs are modified as paddles and the animal can swim. Crabs can also move very well laterally, which their cousins are not so good. There are over 4500 species of crabs and they differ from shrimps and lobsters in the fact their abdomen flexes beneath their body – you do not see the “tail” you see in a lobster or shrimp – but its there. The crustaceans include many different kinds of arthropods – most notably are the crabs, shrimps, and lobsters. It is at this stage we call them “soft shells”. The salts and minerals it removed during pre-molting are now used to harden the new shell – which can take a couple of days. Because of the softness of the body after molting, this is usually done under the cover of darkness for protection. When they emerge, they are completely soft and about 30% larger than before – it is amazing to see this large crab emerge from the small shell it once lived in.
#Blue crab eggs crack
The crack is usually between the cephlathorax and abdomen. To molt, crustaceans will remove some of the salts and minerals from the shell into their tissue, this weakens the shell enough to separate it. Crustaceans tend to molt about 10-11 times each year and typically in the summer months.
![blue crab eggs blue crab eggs](https://addictivereefkeeping.com/wp-content/uploads/2019/04/1213WEB_boyd_1486679120.jpg)
![blue crab eggs blue crab eggs](https://i.pinimg.com/originals/6d/48/10/6d4810ec426dd8b401179c8a4c0e71d8.jpg)
This exoskeleton must be periodically shed (molting) so they can continue to grow. Like all arthropods, their body are completely covered in a chitinous shell that serves as their exoskeleton. Insects typically have a head, thorax, and abdomen – however, in the crustaceans the head and thorax are fused into what is called a cephlathorax and covered with a section of the shell called the carapace.
![blue crab eggs blue crab eggs](https://3.bp.blogspot.com/-tWWQvUSvZlI/VWTWIo1h92I/AAAAAAAAQbM/yCwhWnPdykw/s1600/crabeggs.jpg)
Crustaceans differ from insects and arachnids in that they have five pairs of legs and two sets of antenna. Blue crabs are one of the few crabs with swimming appendages.īut who is this crab that we enjoy so much? What do we know about it?Īs you probably already know, it is one of an estimated 30,000 species of arthropods we call crustaceans.