Haji Ali is a iconic landmark of Mumbai. The shores of Mumbai are rich in marine life. The rocks and puddles around Haji Ali are no exception. These are images from an Sunday evening spend exploring these rocks at low tide.
One of the marine life forms we came across was thick pink bud-like creature. We were wondering what it was when an expert told us it was a sea anemone. But anemone have tentacles!
The moment the rock was put in water the tentacles opened and the bud transformed into the image we have of a sea anemone. Sea anemones are simple creature that have tentacles around a mouth. The mouth opens into a digestive cavity. There is only one way out of this digestive cavity, the mouth. The anemone takes food from the mouth and put out what remains of the prey through the mouth. The tentacles have cnidocytes, cells that have a paralysing toxin. The toxin is both a defence and for paralysing prey to capture it. Most anemones small and vary between 1-5 cm (0.4 to 2.0 in) in diameter and 1.5-10 cm in length. The largest ones can exceed a meter.
This shell was moving to fast for a snail. It was moving fast because it was not a snail. The snail was long gone and a hermit crab had made the shell its home. When the shell was turned over the crab withdrew into the shell. This was the best shot I could manage.
But swimming in a nearby puddle was this hermit crab. Hermit crabs are not true crabs but related crustaceans. Unlike crabs they have a soft underbody and need protection. They get protection from scavenged mollusc shells which they make their home. A hermit crab needs to seeks a new shell to keep up with increasing size. Shells are limited in supply and there can be vigorous competition for what is available.
The star of the evening was this colourful porcelain crab. It’s body had an intricate design. There was something unusual about the porcelain crab. It had tentacles. Crabs do not have tentacles, lobsters do. But lobsters have a long body and a tail. The porcelain crab is an example of carcinisation. Carcinisation is a evolution of a crustacean to a crab-like form from a non-crab-like body. Porcelain crabs are related to squat lobsters.
Crabs move on four pairs of legs. The porcelain crab appears the have three pairs of legs. The fourth pair of legs are very small and not visible. The tails are kept folded under the abdomen and can be used for swimming. They are called porcelain crabs because the are very delicate. When cornered that can shed a limb to divert attention and escape.
Finally there was this juvenile crab. I don’t know what it will grow up to be.