(Ed Note: The scientific name at the start of the video is not correct.) The sea pen, Ptilosarcus gurneyi, is a colonial cnidarian in the same class as the anemone, the anthozoa. One polyp has been modified to form the body, while the fringes of the “feather” contain numerous small feeding polyps. Typically we find it living in a mud/sand substrate. It is rare around Race Rocks. The only population we have found is this one with a few individuals occurring at 15 metres on the North-West corner of Great Race Island. Note the small burrowing tubeworms in the mud around the organism. This specimen was videoed by Wynne Lawrence and Jean-Olivier Dalphond, both students at the Lester B. Pearson College.
General Description:
The sea pen, Ptilosarcus gurneyi, is a colonial cnidaria in the same class as the anemone, the anthozoa. One polyp has been modified to form the body while the fringes of the “feather” contain numerous small feeding polyps.
Habital:
Sea pens are marine organisms: typically they are found living in a mud/sand substrate at least 3 inches (7.6 cm) deep. It is rare around Race Rocks, with a few individuals occuring on the North-West corner of Great Race Island. Note the small burrowing tubeworms in the mud around the organism.
Feeding:
The polyps feed on detritus, zooplankton (baby artemia), and possibly (according to The Reef Aquarium Vol. Two) phytoplankton.You should offer your Sea Pen Artemia nauplii, Daphnia, pulverized flake food, and detritus stirred up from the bottom of the tank.
Predator:
Predators of the sea pen are two nudibranchs, one the very large 3 inches(7cm) nudibranch, Armina californica and the other Mediaster aequalis, Rose Star Crossaster papposus and the Leather Star Dermasterras imbriacata.
Reproduction:
We don’t know the reproduction of sea pens whether by sexual or asexual means.
References:
http://www.fishroom.com/library/seapen.html
http://www.lanecc.edu/science/zonation/seapen.htm
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Subclass: Octocorallia
Order: Pennatulacea Verrill, 1865
Suborder :Subsessiliflorae
Family :Pennatulidae Ehrenberg, 1834
Genus:Ptilosarcus
species:gurneyi
(Ptilosarcus gurneyi)
Common name: orange sea pen
- An interesting feature of their symmetry is glide reflection. As described In 2-dimensional geometry, a glide reflection (or transflection) is a type of opposite isometry of the Euclidean plane: the composition of a reflection in a line and a translation along that line.
Return to the Race Rocks Taxonomy and Image Gallery
Other Members of the Class Anthozoa at Race Rocks.
 Return to the Race Rocks Taxonomyand Image File |
 The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.
Original: Dec 2002, Joshua Columbus ( Burma) year PC yr 29). additions by G.Fletcher 2018 |