Etymology regalis – Latin = ‘of or pertaining to a king’ Crinoidea – Greek from krinon – ‘a lily’
They’re not plants – Despite their resemblance to flowers, are not plants. They are echinoderms – animals characterized by their rough, spiny surface and 5 fold symmetry.
They’re not starfish – They are related to starfish in that they are both echinoids. Like starfish, Crinoids usually have 5 fold symmetry.
They eat with their arms – They are filter feeder and they wave their feathery arms which are covered with a sticky mucus to capture food -floating detritus. The feathery arms have growths called pinnules. The pinnules have rows of tube feet on each side of a groove running down the center. The tube feet that cover the arms pass the food to the center where it is put into their mouth.
Crinoids are old… really really old – They have been around since the Ordovician period – 490 million years ago. Paleontologists however, think they could be even older than that.
You’re more likely to find a crinoid fossil than you are living crinoid – Crinoids today are relatively rare however they were once plentiful and diverse. These echinoderms were at their height during the Paleozoic era (544 to 245 million years ago ). They could be found all over the world, creating forests on the floor of the shallow seas of this time period. There were so many in places, that thick limestone beds were formed almost entirely from their body parts piled on top of each other.
Why would anyone get excited about T. rex, when you have crinoids !
Multipore Sea Star – Linckia muitifora Interestingly the Multipore exhibits autotomy (self amputation) and often sheds one or more arms. In this process, the arms become detached at various positions and each can grow into a new individual. This happens with such frequency that it is considered to be a means of asexual reproduction. Few individuals are found that do not exhibit some evidence of prior autotomy. Individuals always lose their largest arm to autotomy. From the “tail” of the comet, the arm that was dropped off, 4 arms are slowly growing back to form a new complete sea star. As the process continues, the little arms grow bigger, and they will eventually end up looking like stars again. It appears that most of the populations can be made up of these comet individuals. The sexual (gonochoric) produced embryos hatch into planktonic larvae spending up to two years in this stage before settleing and metamorphose into pentamorous juveniles which develop into young sea stars with stubby arms.
In a study on Hawaii, it was found that the detachment of an arm is not caused by a sudden snap. Most fractures take place about 1 inch from the disk. A small crack appears on the lower surface which spreads to adjacent parts, then the tube feet on the arm and the body pull the two parts of the animal in opposite directions. The event may take about one hour to complete. The damaged tissues take about 10 days to heal and the animal grows a new arm over the course of several months. The detached arm is known as a “comet” and moves about independently. It takes about 10 months to regenerate a new disk with arms 0.5 inch in length.
Sea stars can probably undergo asexual reproduction more easily than other animals because they have most of their organs repeated in each of their arms. Also, they don’t have a centralized nervous system, it would probably be a trickier thing to do if they also had to regenerate a full brain. Because of the position of their mouth, it is also one of the first thing to be regrown, so they don’t have to starve for too long before they can feed again. If many species of sea stars can regrow a missing arm, only a few can, like Linckia multifora, regrow a full animal from just an arm.
Etymology Linclda – The genus is named after the German naturalist Johann Heinrich Linck muitifora – multi– ‘much or many’ and +fora = ‘forum’?
Halley’s Comet is arguably the most famous comet. It is a “periodic” comet
and returns to Earth’s vicinity about every 75 years, making it
possible for a human to see it twice in his or her lifetime. The last
time it was here was in 1986, and it is projected to return in 2061.
Turtle Fact Adult female sea turtles are literally magnetically drawn to the comforting beaches here they were hatched. What’s more, scientists suspect that tiny magnetic particles in the sea turtles brain enable them to detect unique magnetic signatures given off by beaches, such that they can return to them after ultra-long journeys.
Creole wrasse – Clepticus parrae – are protogynous hermaphrodites; the largest fish in a group is a dominant breeding male, While smaller fish remain female. If the dominant male dies, the largest female changes sex.
Protogyny is the most common form of hermaphroditism in fish in nature. About 75% of the 500 known sequentially hermaphroditic fish species are protogynous.
Wrasses are always on the go during the day, but are the first to go to bed and the last to rise.
Etymology Clepticus: Greek, kleptikos = ‘related to thieves’