Shells

In Madeira, as indeed elsewhere, this word has a restricted meaning: it denotes only the calcareous shells of two-valved marine molluscs, known to specialists as lamellibranchs or pelecypods. Those with a single valve, or gastropods, are generally called búzios if they are marine and not very small; if they are terrestrial or freshwater, they are mostly called caracóis. (See Búzio and Caracóis.)

Of the sea molluscs, some live in the tidal zone; others, the great majority, live in more or less deep water, on sand or mud, or on beds where corallines abound – those strange forms of calcareous algae that look more like stones than plants.

Bivalves are rare in the first of these zones. Nevertheless, Cardita caliculata, Lasaea rubra and a few other small species are found there, living in recesses of the rock or covered by algae. In this same region live, among the univalves, two or three species of Littorina and four species of Patella, the latter all edible (see Limpets); Haliotis tuberculata, beautifully lined with mother-of-pearl; several species of Trochus, one of which, the caramujo (Trochus colubrinus), is edible and sought as bait for fish; Mitra cornicula, M. zebrina, Columbella cribaria and C. rustica. In the rock pools, the small Fossarus ambiguus and the tiny Rissoa picta are sometimes abundant at certain spots, such as Baixa Larga (‘broad shoal’) and Pôça do Governador, east of Ponta da Cruz (‘point of the cross’).

Among the gastropods of this level, a humble-looking whelk deserves special mention: Purpura haemastoma, or the búzio de marcar roupa (linen-marking whelk). Ordinary people eat it as shellfish, and it is remarkable for possessing a gland that secretes a dye capable of giving a beautiful purple colour. Because this gland is foul-smelling, caustic and very bitter, it is called fel de búzio (whelk’s gall). This mollusc is known to have been used by the ancient Romans and other peoples to dye that rich and famous fabric, purple, but it ceased long ago to have any industrial use. Even so, in these islands the odd individual still uses its dyeing property to mark white linen, perhaps out of an old traditional custom that is, moreover, dying out day by day. The process simply consists of dipping the tip of a small stick in the viscous substance of the gland, drawing the desired marks or letters on the fabric and then exposing them to the direct rays of the sun. The colour, at first a citrine yellow, turns green through various shades and finally to a reddish or blackish violet, depending on the thickness of the layer applied, leaving the stroke indelibly printed. Fel de búzio is also used to treat impetigo.

In the coastal zone immediately beyond the tidal zone one may find the elegant Pinna rudis, commonly called leque (fan), which is the largest bivalve known in these islands; or the large, thick Spondylus Powellii, firmly attached to the rocks by one of its valves. There are also many whelks, among them the genera Triton, Cypraea, Pleurotoma, Nassa, Columbella and Murex, not to mention the minute forms of the genus Rissoa, the most widely represented in these seas, of which some 30 species have been recorded.

Moving into deeper water, one can gather on the nullipore beds, which are abundant in the bay of Porto Santo, near Caniçal (‘reed bed’) and Garajau (‘tern’), and at other points on the south and north of Madeira, various graceful species of Pecten, such as P. pusio, P. Jacobaeus, P. corallinoides and P. pes felis; the lovely shells of the genus Venus, among them V. casina, V. verrucosa and V. chione; the velvety Pectunculus glycimeris; the snow-white Lima squamosa; Cardium tuberculatum, C. norvegicum, C. aculeatum and many others, which are not hard to obtain where the bottom is flat and suitable for working a dredge. Among the numerous univalves, besides those already mentioned, are the genera Trochus (Zizyphinus), Turbo, Bittium, Cerithiopsis, Scalaria with 15 recorded species, Aclis with 6, Odostomia with 22, Eulima with 12, Ranella, Natica, Ringicula, Bulla, Philine, Limacina and many others, some of which are not rare on the muddy bottom of Funchal harbour.

Further out, in the coral zone, an inedible species of oyster is abundant: Ostra cochlear, with its variously coloured shell. There, together with Chama gryphoides, lives Avicula hirundo, with its graceful outline and pearly interior, a close relative of the pearl oyster, which hangs like a strange fruit from the branches of the so-called sea trees (Gorgonia verrucosa). At depths of about 90 braças the curious Venus effossa is found, at such various places as the Ponta de São Lourenço and Ponta do Garajau and the waters around the Ilhéu de Cima (‘upper islet’), off Porto Santo. Among the univalves of this deeper zone, mention should be made of the rare Mitra exilima, dredged west of Garajau, Trophon Lowei, Murex babelis and the pelagic species of the genera Atlanta, Limacina, Cavolina and Clio, whose skeletons settle in myriads on the ocean floor, besides many others that it would take too long to list.

The sea casts countless shells onto the great beach of Porto Santo, above all during the high spring tides of the equinoxes. Women and children gather them in small quantities, which are pooled and sold by the alqueire (dry measure for grain; as a land measure c. 900 m²) to the trinket dealers of Funchal. These dealers resell them by weight for decorating brooches, small baskets, flower vases, garden grottoes, etc.

Throughout the year the pelecypods are found in great quantity on that beach: Tellina, incarnata, Cardium tuberculatum, Diplodonta trigonula, Donax venustus, Anphidesma, castanea; and, less numerous, Arca tetagrona, Pecten pusio, Thracia papyracea, Diplodonta rotundata, Lucina divaricata and L. reticulata. The mussel (Mytilus edulis), an exotic species, also reaches that island, though rarely, carried from afar by the ocean current on pieces of wood or cork. The gastropods rolled on the sand are no more numerous; among the more or less interesting ones recorded are Emarginula fissura, Trochus Bertheloti, Rissoa cancellata, Bittium depauperatum and B. incile; the pelagic species Janthina commnunis and J. pallida, often attached to the hydromedusa Velella limbosa, particularly when a strong wind blows from the open sea; various species of Solarium;

Triton reticulatus, Ranella marginata, R. scrobiculator, R. Thomae; and finally the beautiful and rare Cassis crumena and the common C. sulcosa. The latter is called the búzio de chave (key shell) on Porto Santo, because the islanders tie it to the keys they carry in their pockets, evidently to keep them from going astray.

Besides the two classes mentioned, the amphineurans and cephalopods have representatives in these seas. Among the latter appears Spirula Peronii, whose shell the sea at certain times deposits by the thousand on the beach of Porto Santo. Yet not once has the animal itself been found: it is so rare that the museums of the whole world hold only a very small number of specimens, although the species is spread through all the oceans. Rarely, on that same island, the beautiful shell of the female Argonauta argo is also found. (See Cephalopods.)

In Madeira no native bivalve mollusc is used as food, although many of them are tasty. On the other hand, certain univalves and cephalopods are eaten.

For the study of Porto Santo folklore, the names used on that island, above all by children, for the commonest shells or those they like best may perhaps be of some interest. They are indeed attractive and cheap toys, costing only the effort – itself an amusement – of searching for them along the wide sands of the beach.

These picturesque, childlike names are based on a likeness of shape or colour to domestic animals or everyday objects. Zizyphinus, for example, with its tall conical shape, calls to mind the old carapuça (traditional Madeiran cap shaped like an inverted funnel) of the Madeiran peasant or countryman; the various shades of Columbella rustica, in which orange predominates, recall the oxen of that island; the spotless white Natica porcellana and the perforated Haliotis tuberculata have been likened to a sheep and a sieve respectively; and so on. It should also be noted that the words concha and buzio here have a meaning restricted to particular species.

All this, however, like many other expressions of regional character, is fading day by day, owing to the inevitable change that is bringing the island into closer contact with outside civilisation, and which will end by destroying the original things its isolation had produced.