Tag Archives: Queensland seashells

Nerite Shells at Port Douglas

Posted on by
2

Mostly Nerite Shells (Nerita costata Duclos) in a part-submerged rock crevice at Port Douglas

Nerite Shells are very common inhabitants of rocky shores on the Queensland coast in Australia; and they generally have a wide Indo-Pacific distribution. There are several species but the specimens shown here are Nerita costata Gmelin and were photographed at Port Douglas.

They have a characteristic appearance with thick black rounded ridges spiralling around the shell whorls, with lighter coloured furrows between them. The spire is blunt. The aperture opening is roughly semicircular with a specific arrangement of protruberances or ‘teeth’. The odd-shell-out in pictures 1 and 2 is a Mulberry Shell or Granulated Drupe (Morula granulata Duclos) which has an odd look with spirals of dark rounded bumps vaguely resembling a bunch of grapes or similar.

Mostly Nerite Shells (Nerita costata Duclos) in a part-submerged rock crevice

Dry Nerite Shells in a rock crevice at low tide

Individual Nerite Shell in thin film of water.

Outer surface of Nerita costata

Under surface of Nerita costata showing aperture and operculum

COPYRIGHT JESSICA WINDER 2013

All Rights Reserved

Mud Creepers

Posted on by
Reply

Mud Creepers (1) - Empty shell of Telescopium telescopium L., Mud Whelk, at Cairns, Queensland, Australia, with remains of an oyster shell and barnacles attached.

Telescopus by Dominic Johns - A sculpture on the esplanade at Cairns, Queensland, Australia. Mud Creepers are a common sight on the tidal mud flats at Cairns in Queensland, Australia. Also called Telescope Shells, Mudwhelks, Telescopic Creepers, or Mangrove Mud Whelk. The Latin name is Telescopium telescopium L. They are so emblematic of the place that they have been glorified by a fantastic piece of sculpture by Dominic Johns on the Esplanade.

The reality, however, is that this large gastropod marine mollusc – living on the glutinous muds exposed by the ebbing tide – is not the most attractive of seashore creatures, in fact, a bit creepy. It is dark in colour, about 6 inches long, and the shell is very thick and heavy, The protruding muscular foot and tubular siphon of the animal are hard to distinguish from the mud itself but I believe the flesh is edible.

Telescopus by Dominic Johns - A sculpture on the esplanade at Cairns, Queensland, Australia.This sea snail seems to struggle as it drags its weighty shell across the mud in strange irregular movements without the supporting medium of water. The furrows incidentally ploughed by the shells leave networks of trails on the mud. In life the shells are often caked with mud but empty shells washed up on the beach show there is actually a great striped pattern.

Mud Creepers (2) - Empty shell of the Mud Whelk or Mud Creeper, Telescopium telescopium L held to show the apertural end at Cairns, Queensland, Australia.

Mud Creepers (3) - Empty shell of Telescopium telescopium L., Mud Whelk, on the shore at Cairns, Queensland, Australia.

Mud Creepers (4) - Empty shell of Telescopium telescopium L., Mud Whelk, on the shore at Cairns, Queensland, Australia, with remains of an oyster shell and barnacles attached.

Mud Creepers (5) - Empty shell of Telescopium telescopium L., Mud Whelk, on the shore at Cairns, Queensland, Australia.

Mud Creepers (6) - Empty shells of Telescopium telescopium L., Mud Whelk, on the shore at Cairns, Queensland, Australia. One shell has barnacles attached.

Mud Creepers (7) - Empty shell of Telescopium telescopium L. on the beach at Cairns, Queensland, Australia, with fiddler crabs.

Mud Creepers (8) - Empty shell of Telescopium telescopium L., Mud Whelk, on the shore at Cairns, Queensland, Australia. The shell has barnacles attached.

Mud Creepers (9) - The tidal mudflats at cairns, Queensland, Australia - habitat of Telescopium telescopium L., the Mud Creeper, Mud Whelk, Telescopic Creeper, or Mangrove Mud Whelk.

Mud Creepers (10) - The tidal mudflats at Cairns, Queensland, Australia - habitat of Telescopium telescopium L., the Mud Creeper, Mud Whelk, Telescopic Creeper, or Mangrove Mud Whelk.

Mud Creepers (11) - The tidal mudflats at Cairns, Queensland, Australia - habitat of Telescopium telescopium L., the Mud Creeper, Mud Whelk, Telescopic Creeper, or Mangrove Mud Whelk.

Mud Creepers (12) - Living specimen of Telescopium telescopium L., the Mangrove Mud Whelk, crawling through the glutinous mud at low tide, its heavy shell making a furrow behind it as it is dragged along, Cairns, Queensland, Australia.

Mud Creepers (13) - Trails left in the mud where living Telescopium telescopium Mangrove Mud Whelks have dragged their heavy shells along when the tide is out.

Mud Creepers (14) - Empty shell of Telescopium telescopium L. on the beach at Cairns, Queensland, Australia.

Mud Creepers (15) - Empty shell of Telescopium telescopium L. on the beach at Cairns, Queensland, Australia.

Mud Creepers (16) - Empty shell of Telescopium telescopium L. on the beach at Cairns, Queensland, Australia.

COPYRIGHT JESSICA WINDER 2013

All Rights Reserved

Trinity Beach-combings

Image

Reply

An assortment of seashells and pebbles from the strand-line at Trinity Beach, Queensland, Australia

COPYRIGHT JESSICA WINDER 2012

All Rights Reserved

A seashell like an ammonite

Posted on by
6

Empty shell of the marine Cephalopod mollusc Spirula spirula L. - Common Spirula or Ram's Horn, on Myall beach, Cape Tribulation, in Far North Queensland, Australia (1)

Most seashells with a coiled shape are Gastropod molluscs – like the common winkles and whelks. However, the small, loosely-coiled seashell from Myall Beach at Cape Tribulation in Queensland, Australia, shown here belongs to the Cephalopod molluscs.  The most commonly-occurring Cephalopod molluscs at the present time are animals without external shells. Examples of these include the squid, and cuttlefish -  which have a reduced internal skeleton – like the familiar cuttlefish bones found so frequently on beaches. Octopuses are also Cephalods.

We know from the fossil record that, in the distant past, there were many cephalopods with external coiled shells; and these were called ammonites. There are several earlier posts in this blog about fossil ammonites. There is a similar loose coil shaped Cretaceous ammonite called Aegocrioceras quadratum (Crick) found in the UK.

There are a still a few modern Cephalopod species which retain an ancestral-style external coiled shell such as the ones found as Ammonites. These include the Nautilus and and Paper Nautilus group of species. Less commonly known is the single species of the single genus belonging to the family Spirulidae – shown in the photographs here. This is the Common Spirula or Ram’s Horn (Spirula spirula L.). You can see through the fragile translucent shell to the internal septa or partitions that divide the shell up into the compartments that are so familiar from ammonite fossils. The octopus-like animal itself would have in life mainly occupied the outermost compartment, with its swimming tentacles protruding from the circular opening.

Apparently the shell of the Common Spirula is found on beaches all over the world but the living animal is rarely seen because it is a pelagic deep water form. This particular shell specimen has washed ashore with minute goose barnacles or stalked barnacles attached to it. The small balls of sand on the beach with the shell are made by the many burrowing Bubbler Crabs that inhabit this tropical shore.

Empty shell of the marine Cephalopod mollusc Spirula spirula L. - Common Spirula or Ram's Horn, with sand pellets made by the Bubbler Crabs that burrow into the shore, on Myall beach, Cape Tribulation, in Far North Queensland, Australia (2)

Empty shell of the marine Cephalopod mollusc Spirula spirula L. - Common Spirula or Ram's Horn, with sand pellets made by the Bubbler Crabs that burrow into the shore, on Myall beach, Cape Tribulation, in Far North Queensland, Australia (3)

Myall Beach, Cape Tribulation, in Far North Queensland, Australia, where the empty shell of the marine Cephalopod mollusc Spirula spirula L. - Common Spirula or Ram's Horn, was found (4)

COPYRIGHT JESSICA WINDER 2011

All Rights Reserved