Photo Peter Southwood, from Bellows Rock
Photo Peter Southwood, from Bellows Rock
Photo Guido Zsilavecz, from Long Beach
Photo Guido Zsilavecz, from Long Beach
This string jelly is very similar in appearance to Apolemia uvaria, which has been identified from the Mediterranean and Atlantic ocean, so we think it may be the same or a similar species, and for the present will call it Apolemia cf uvaria.
A. uvaria is planktonic and is usually found in the top 100 m of water. It feeds on other planktonic organisms such as crustaceans, polychaetes, mollusks, tunicates, and even small fishes.
Usually lurking in the inky darkness of the midwater, the siphonophore Apolemia acts like a living drift net, with a length which can exceed 30 meters. With tentacles spread out, it is a formidable predator on small creatures inhabiting these depths. Apolemia is a physonect siphonophore and thus has an anterior gas float and set of swimming bells. The vast majority of the body is formed by the elongate stem region with its feeding and reproductive structures. Since the stem is exceedingly delicate, you will never find the entire siphonophore, or even very long segments, near the surface. You are far more likely to see sections of no more than a meter or two in length. Typically the stem sections have a pinkish white colour and drift with the currents, unable to move on their own. The stinging cells contain a strong poison which is painful to humans.
Classification:
- Phylum: Cnidaria
- Superclass: Hydrozoa
- Class: Hydromedusae
- Subclass: Siphonophorae
- Order: Physonectae
- Family: Apolomiidae
Thanks to Peter Southwood for this contribution.
Introduction to the Zooplankton of the Benguela Current Region. MJ Gibbons.
Marine Fauna Gallery of Norway:
www.seawater.no/fauna/index.htm
www.seawater.no/fauna/Nesledyr/apolemia.htm
Pacific Coast Invertebrates. D Wrobel and C Mills, 1998.