Vol.38 No.1 April 2008
Total Page：16
File Type：pdf, Size：1020Kb
VOL.38 z NO.1 z APRIL 2008 PALLIDULA Page 2 COVER PAGE Buccinum undatum “littoralis” King – Photo and collection John Fisher More information on page 12 PALLIDULA Page 3 ROSTRATED COWRIES OF EAST SINAI by E. L. Heiman Rostration is the extension of the shell extremities, resulting in their becoming beaked to a certain degree, which is not characteristic to a species. There are cowries of East Sinai which normally have shells with extended (rostrated) extremities and it is one of their diagnostic characters, for example Pustularia cicercula (Linnaeus, 1758), Pustularia globulus brevirostris Schilder & Schilder, 1938, and Erosaria nucleus (Linnaeus, 1758). In other cowries in that area an excessive extension of the shell extremities (rostration) is rare. Several different forms of this phenomenon in cowries of East Sinai are discussed in Heiman (2002); perhaps the most striking examples of such shells can be seen in Figs. 1-6. Usually both ends of the shell are rostrated but sometimes this happens with only one of them as can be seen in Figs 7-11. The shell of Mauritia arabica grayana Schilder, 1930 pictured does not look like a senile specimen and there seems to be no indication of serious damage to the shell. Still its anterior extremity is turned down and covered by an excessive callous deposit producing the effect of rostration. In rostrated shells of New Caledonia and Queensland, Australia the extremities are usually turned up that in extreme cases produce a “boat-like” effect. Perhaps in the future new conchological information will help us to explain these phenomena producing such unusual shells. Fig. 1 & 2 - Erosaria turdus pardalina (Dunker, 1852); 47.8 mm Fig. 3 & 4 - Erosaria nebrites (Melvill, 1888); 30.8 mm. Fig. 5 & 6 - Erosaria macandrewi (Sowerby, 1870); 27.4 mm Fig. 7 – 10 - Mauritia arabica grayana Schilder, 1930; 80 mm. PALLIDULA Page 4 Shelling in Istria - North Eastern Adriatic by Graham Saunders In April 2007 I was able to spend a few hours in the water (or mud) near Piran, Novograd and Rovinj. Individual forays did not exceed forty minutes, as the water, particularly at Piran, was very, very cold. A couple of other sites were cursorily inspected. Piran - North facing, a rocky foreshore below cliff path. 20th April 2007. (Pictured right) Boulders with Patella caerulea, Osilinus and Gibbula were riddled with borers such as Lithophaga and Gastrochoena. No Chitons were seen. The Patella’s are very large, beautiful and thin shelled. It was not possible to remove these without damaging them so none were taken. Piran - West facing below the promenade. 21st April and 22nd April 2007. An area of wave swept boulders and rock with some loose stone and a little weed. The seabed shelves to deep water. The predominant gastropods were the Hexaplex trunculus with smaller numbers of the largest Haliotis lamellosus I have seen, and Calliostoma, Pisania, Osilinus and Gibbula. The most interesting find was a population of Chlamys glaber. These were restricted to a low tide depth band of 0.4 metres to 0.8 metres. Almost all of them were near the top of clean, curved rock domes, all attached by byssus. A couple were lower on the curve. They were below the thermocline in really cold water. Most were light colours. I had always assumed that they lived in deeper water but I was evidently wrong. There was a small number of Chlamys varia under stones, all were dark coloured. As previously mentioned, the water was very cold, even with wetsuit. The maximum functional time in the water was about 35 minutes. The church in Piran has a spectacular font incorporating a huge Tridacna gigas (pictured left). Izola (or Isola if you are Italian) - evening, 21st April 2007. I checked the harbour area in passing. There were two particularly large Bolma rugosa crawling in shallow water on the lower harbour steps. On the harbour wall near a scallop trawl, I found a pile of Corbula gibba with one Dentalium and one Hinia. There were older broken Muricids and Aporrhais scattered nearby. Piran, - 22nd April 2007. They have a marine aquarium near the harbour with quite a few molluscs including Mitra zonata though I never saw one in the wild. They were unaware of the Chlamys, which lived 180 metres away. I persuaded a fisherman to bring back his net cleanings. He was away for less than 3 hours and had several items including a red sponge, potentially Suberites domuncula (olivi) but at 64mm it was more than twice the size reported as maximum for that species. This grows around the home-base shell of a hermit crab. In this case the original shell was a tiny Polinices poliana. When I was taking the sponge apart I discovered that Bittium had colonised it burrowing throughout Piran Harbour and Marine Aquarium its structure. There were 18, all clean specimens. Other live shells were Bolinus brandaris and Hexaplex trunculus but better specimens of these were in clear view crawling on the harbour wall. There is no easy access to the water. You need a net on a long pole. In the evening we ate at the Tratoria at the northern end of the promenade. "Moules" were on the starter menu. When these appeared they were actually Lithophaga which I knew was illegal Specimens from the in Croatia because of the damage done to the harbour walls by restaraunteurs. I was Fisherman’s nets not at that time aware they are on the CITES list. The Croats hype them as an illegal aphrodisiac. They do not taste as good as Mytillus and the aphrodisiac story is a con! These were the largest specimens I had ever seen. PALLIDULA Page 5 Novograd - Croatia, or rather a couple of km up the coast. 24th April 2007. An area of muddy stones and silty shallows with nothing very exciting; there was a lot of scallop debris and I managed to reconstruct some original pairs. They were all Pecten jacobeus (if we are still recognising it as a species). Conus are in the area but they are all horridly eroded specimens. Opatja - 26th April 2007 The rocks were almost barren and there was little in the way of marine life. Rovinj - 27th April 2007 We took the ferry to the offshore islands controlled by the Istria Holiday complex. A causeway joins the large and small islands. On the south side the water is shallower and warmer. Thericium are white and the range of species is not exciting. A few feet away on the other side the water is colder and less shallow. The Thericium are all patterned brown and more exciting things can be found such as a variety of Fissurella, but best of all was a rock weighing about 15kg from about 1.5 metres of water. Underneath, between a number of beautiful white Chama were five Galleoma turtoni, each at the bottom of a shallow pit. I did not consider that the Chama could be removed without damage so they returned to the water as found. The shells seemed very small in relation to the size of the animal and at rest the whole thing was concave. We have seen photographs that appear to demonstrate that this animal travels with the two shells half closed. These are abnormal and misleading. A relaxed Galleoma travels extended and flat or follows the contours. Only a worried Galleoma will travel with shell half closed. A frightened Galleoma retreats totally into the shell though this looks totally impossible till you see it happen. Northern Sardinia 2002 - Some notes on a week in May by Graham Saunders These notes relate to two main areas and several secondary areas: Cala Piscaria facing North West, the South East peninsula of Caprera and several minor collecting points in Northern Sardinia and a few hours below the cliffs of Bonefascio ten miles over the water in Corsica. Some species were widespread over most areas though others were confined to single pockets where 60% of the records for an entire reef came from an area less than one metre square. The only larger gastropod to be found in any numbers was Hexaplex trunculus though, where one found flat rock in shallows, there were generally a few Fasciolaria lignaria. In most areas, Ceriths made up the bulk of the molluscan fauna. There were fewer microshells than I would have anticipated, even in suitable habitats, and there was a distinct shortage of Trochidae. I found a single live Trivia pulex in weed in about 10 cm of water. I had always assumed that they lived in deeper water. Assumptions are often counter productive. We took the car over to the Isla Magdalenas which include wilderness areas and a national park. There are many sandy bays which can only be reached on foot by overgrown tracks. The islands are small but you could spend weeks exploring. We found a perfect small beach close to an abandoned factory with jetty and slipway. It was on the eastern side of the island but very sheltered. In shallow water my attention was immediately drawn to an exceptionally large and perfect Dentalium and a scattering of smaller fresh material including some interesting Turrids. Weed washing and stone turning produced lots of smaller material including some nice Engina bicolor. As always, there were more of Bittium than any other species with Ceriths (not large) second in abundance. PALLIDULA Page 6 Fossil Pleurotomariidae by Adrian Brokenshire Following a recent article by John Batt on modern Pleurotomariidae in vol.36, No 2, Oct 2006, I thought I would have a go at an article on some fossil 'Pleurotomariid' gastropods.