The Crab Nebula was formed by a supernova that occurred just 900 years ago. This event was recorded by Chinese astronomers who described that one of the stars in the present-day constellation Taurus had suddenly grown as bright as the full moon. Over a period of two years, the supernova faded, leaving behind wispy remnants that are now recognized as the Crab Nebula. As the most easily observable supernova remnant, this nebula has been extensively studied. Studies show that the material within the central portion of the nebula changes within a time scale of only a few weeks.
Zebra urchin crab, Zebrida adamsii
Photo © Teresa Zubi
Flat rock crab, Percnon planissimum
Photo © Teresa Zubi
Sea Star Swimmer Crab, Lissocarcinus polybiodes
Photo © Teresa Zubi
Harlequin swimmer crab, Lissocarcinus laevis
Photo © Teresa Zubi
Mosaic boxer crab, Lybia tessellata
Photo © Teresa Zubi
Lumpy box crab, Calappa gallus
Photo © Teresa Zubi
Horned Crinoid Crab, Ceratocarcinus longimanus
Photo © Teresa Zubi
The hermit crab, Pagurus prideaux, is always seen with its protective anemone cloak. It does not have to find a bigger shell as it grows because the cloak anemone secretes a horny extension.
Xiphosurids are an ancient marine group that dates from the Cambrian period. There are only three genera (five species) living today. These are what we commonly know as the horseshoe crabs.