5 January 2012

A glimpse of invertebrate marine life of Newfoundland (part 6)

The brittle star Ophioderma brevispina.

I made two snorkeling trips: one at Open Hall and one at Salvage. Have a look at this post for other pictures of Salvage and Open Hall. Apart from Asterias, Eudendrium, an unknown species and Tamiasciurus all photo's were made at Salvage.

The green sea urchin, Strongylocentrotus droebachiensis.

Detail: between the spines you can see tubefeet. They use the tubefeet for locomotion and to attach weeds, (particles of) shells etc. It is said for camouflage, but some urchins do and some don't at the same spot. And those that camouflage themself, regurlarly make a lousy job of it. See for the picture further on of the green sea urchin carrying a (living) periwinkle.
A bit overcrowded?

The tortoiseshell limpet, Testudinalia testudinalis. Just as the green sea urchin and the periwinkle (next photo) they predate on seaweeds and keep the rocks on which they grow 'tidy'.

The common periwinkle, Littorina littorea (NL: gewone alikruik). At left just visible a dog whelk, Nucella lapillus (NL: purperslak).
A lot of shells (mussels) and crabs (Cancer) looked quite eroded. This periwinkle has a lot of scars. I think the slits are caused by crabs. But the holes? Dog whelks drill holes in shells, but these holes are very crude.

The common mussel, Mytilus edulis (NL: mossel).

The acorn barnacle, Semibalanus balanoides (NL: gewone zeepok) in different growth stadia.

The atlantic rock crab, Cancer irroratus. This specimen looked very worn and was quite slow.

This one wasn't slow! The specimens I found were small: up to 8 cm. It can grow up to 13 cm wide. A lot smaller than its European nephew Cancer pagurus, which can grow up to 30 cm wide. For this species and other relatives of Cancer irroratus have a look here.

A gunnel, Pholis gunnellus (NL: botervis) hiding near a green sea urchin. Robbins' description (1986; see literature page) points it to another species: Pholis fasciata, the banded gunnel. I think he is mistaken.

The common starfish, Asterias rubens (NL: gewone zeester) in cometform (NL: komeetvorm). The starfish lost 4 of its 5 legs, which are now regenerating.
The brittle star Ophioderma brevispina wasn't pleased when I turned the rock it was hiding under. Most brittle stars become active at night and quickly hide when exposed to light.
Probably stick hydroids, a Eudendrium species (NL: haarpijpje) growing on bladder wrack, Fucus vesiculosus (NL: blaaswier).

Hardly visible (right/upper halve): Stauromedusa species, stalked jellyfish (NL: steelkwal), another cnidarian but belonging to the Scyphozoa (jellyfishes).

I am not sure, but I think that these very tiny creatures are flatworms (phylum Platyhelminthes).

The lion's mane jellyfish, Cyanea capillata (NL: gele haarkwal). The world's biggest jellyfish with a bell diameter of up to 2,5 metres and tentacles as long as 30 metres! This one was only 30 cm wide. It can inflict painful stings.

The biggest specimen I ever saw, was washed up on a beach in the Oosterschelde. It had a bell diametre of 1 metre and was thin as a dime. Before I found it I was wondering where a strong fishy smell originated from. Yes: this jellyfish!
Not an invertebrate but I can't resist showing this cute American red squirrel, Tamiasciurus hudsonicus. It was running up and down the wharf at Open Hall. It is not native to Newfoundland, but introduced in 1963. In the same year as the chipmunk, which 'Newfies' regard as vermin.