Category Archives: Echinoderm

People say spiders are scary, but I am glad I don’t have crinoids hiding all over my house.

Liparometra regalis - Crinoidia - Feather Stars
Liparometra regalis Crinoidia – Feather Stars

Liparometra regalisCrinoidia Feather Stars

Etymology
regalis – Latin = ‘of or pertaining to a king’
Crinoidea – Greek from krinon – ‘a lily’

Crynoid Facts:

  • 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 !

Robert Bakker – paleontologist

Where is Adam?

Ambon Crinoid Shrimp on Crinoid
Ambon Crinoid Shrimp on Crinoid

Ambon Crinoid Shrimp – “Laomenes Amboinensis sp group”
Trying to identify which species of shrimp this is has proved to be more difficult then I desired. It has become a field of rabbit holes. Each time thinking that I found it it turn out No. I only have one photo of this fellow. To date, nine valid species are known in this genus and they show a wide diversity of morphological features such as shape of cornea and eyestalk, chelipeds and dactyli of ambulatory pereiopods, coloration and host specificity. Although many underwater photographs of these colorful shrimps are available in guide books, magazines and internet, there are rather few taxonomic reports on the species of this genus and most species only have limited confirmed geographical records. Moreover, it is highly likely that more species are present in Laomenes.

Etymology:
In Greek mythology Laomenes is a son of Heracles and Oreia, daughter of Thespius, king of Thespiae, and Megamede; during his hunt for the lion of Cithaeron to free Thespiae from this scourge, Herakles stayed with Thespius for 2 months, as a result all 50 daughters of Thespius and Megamede bore him a son each (except the oldest, who produced twin boys); Laomenes was one of these 51 boys.
 Ambon Island is part of the Maluku Islands of Indonesia +ensis, Latin denoting origin

This is the true color of the shrimp and the crinoid host. I have decided to name him “Skinny Adam L”.

It is a lighter shade red than Maroon 5.

Jon B, jason B said “for crinoid out loud that is a bad joke”.

A Sea Cookie Monster?

Spotted Worm Sea Cucumber - Synapta maculata
Spotted Worm Sea Cucumber – Synapta maculata

Spotted Worm Sea CucumberSynapta maculata – Sometimes growing as long as 10 ft, it is one of the longest sea cucumbers in the world. The 15 tentacles of Synapta maculata surround the mouth and are used in surface feeding. They are about 1 in long when extended and have a short stem and a feather-like blade with thirty to forty pairs of pinnules (secondary branches). The outer surfaces of the tentacles have numerous bulges and are adhesive while the inner surfaces are smooth, with clusters of cilia on the proximal parts. The tentacles are in continuous motion; they flatten themselves against the substrate or seagrass leaf blades and collect food particles by adhesion, then bend inwards until the tips are in the mouth, where the food is scraped off by the buccal (mouth) sphincter muscle. The whole process takes only a few seconds, and several tentacles can deliver their loads at the same time. You can watch them go at https://www.youtube.com/watch?v=7ru1fcsFp1M

Now for the comparison to The Cookie Monster: https://www.youtube.com/watch?v=OqL7jyrXhLs

Etymology:
Synapta: Latin ‘joined together’
maculata: Latin maculosus ‘spotted’

Ambon Crinoid Shrimp a master class in camouflage

Amboinensis Crinoid Shrimp - Periclimenes amboinensis
Amboinensis Crinoid Shrimp – Periclimenes amboinensis

Ambon Crinoid Shrimp or Feather Star ShrimpPericlimenes amboinensis – Hiding among the arms of the crinoid this little shrimp wondered if I could see him.

Small in size, between 1 – 1.5 cm, they can be highly variable in colors – Yellow, White,Black,Blue,Orange,Green,Brown and in combination of colors, all depending on the host Crinoid that it lives on, for camouflage.

Crinoids, also known as “feather stars” or comatulids are harmless, colorful creatures. They are among the most ancient and primitive of ocean invertebrates. Crinoids are Echinoderms (Phylum Echinodermata, meaning “spiny skin”). To feed, they extend their arms to catch bits of plankton or detritus (waste matter) passing in the current, making them “suspension feeders”.

Etymology of amboinensis Means “from Ambon” the island in the Lesser Sunda Islands, Indonesia.

Etymology of Crinoid – Greek word krinon, “a lily”, and eidos, “form”