Star-fish and Sea-urchins, with List of local species

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STAR-FISH AND SEA-URCHINS.

STAR-FISH AND SEA-URCHINS.

BY THE REV. GRAVES LOMBARD, M.A. NATURALISTS know

all sorts of curious creatures in the ocean ; for instance Sea-butterflies, the Sea-cow, the Sea-lion, a Seamouse, Sea-serpents, Sea-slugs, Sea-spiders, Sea-squirts and Sea-urchins. It is concerning the last animals that I wish to say something, more especialy in relation to their burrowing, feeding, locomotion and the radula of their teeth. The small green Sea-urchin (Echinus miliaris, MĂźll.), which is a more typical shore form than the handsome E. esculentus, inhabits rocky coasts. The species is covered with spines which, in allied kinds from warmer seas, may be of great length as well as sometimes thickness and must be handled with caution. Forms allied in structure but not appearance are the burrowing Echinocardium cordatum, to be dug from the bottom near tide mark, though thev are commoner in deep water. Burrowing Sea-urchins, such as Spatangus and this Echinocardium an little heart-shaped kind (Echinocyamus), live in sand ; they feed, like a great many Sea-cucumbers and worms, in mud, spending their days slowly ploughing through it and, as they progress, swallowing great quantities of animalcules by picking up mud-particles by means of especial grasping tube-feet surrounding the mouth. Other animals, like the Ship-worm (:Teredo navalis, Linn.), obtain their food by boring; others again scrape off the various animals and plants which form a crust over the surfaces of rocks, including our commoner Urchins.

They hold on to the rock by their tube-feet and bite off food by means offivelong teeth, which are supported in an intricate skeleton known, on account of its discoverer and shape, as Aristotle's lantern. The muscles of the lantern force the teeth downwards so that they all come together beneath the mouth and thus bite off a circular lump of food, which becomes automatically pushed into the mouth. Other such scraping creatures are the common shore Snails, the winkles (Litorina litorea, Linn.) and Limpet (Patella vulgata, Linn.), both abundant upon the Suffolk coast. Bat their locomotion, by means of great muscular feet, is quite different from that of the Echinodermata. Burrowing Worms, Crustaceans and Sea-urchins all have special devices that enable them to work their way through the sand or mud of the ocean-bed.

Star-fish and Brittle-fish, also Echinodernata, but of the sub-class Hypostomata, crawl about on rocks or in sand and devour any suitable animal they can find, the former seizing it with their tube-feet and the latter wrapping it round with

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their very active arms.

In both cases the prey is carried to the mouth and swallowed ; but the common Star-fish (Uraster rubens, Linn.) is able also to feed upon creatures much larger than itself by the simple and convenient process of protruding its stomach over any animal t h a t it cannot swallow.

They consume great numbers of bivalve Shell-fish, above which they hunch their bodies and gradually force the shell-valves open by a continuous pulling action of their tube-feet ; for, though the occlusing muscles of the Mollusc are much more powerful than these tube-feet, they soon tire, the sustained pull of the Starfish finally conquers, and the shell begins to gape.

Through the orifice the former intrudes its stomach, which probably first poisons and later certainly digests its soft prey's body.

This habit causes Star-fish to be the greatest pest upon beds of Oysters (Ostrea edulis, Linn.) and Musseis (Mytilus edulis, Linn.) ;* also they digest the apparently invulnerable Seau r c h i n ' b y similarly forcing their stomachs down its throat, quite regardless of its teeth.

Our Urchins possess a characteristic feeding-apparatus, consisting of a long and horny ribbon, made of many rows of fine teeth, termed the radula or lingual ribbon.

It is supported by a sustaining framework, over which it is drawn backwards and forwards like a rope over a pulley.

The whole mechanism can be withdrawn into the mouth when at rest, but in usage it is pushed out against the food which it rasps away by continuous sawing movement, eacli piece being pulled back into the mouth and there further chewed by the jaws before being finally swallowed.

This radula is perpetually wearing away, but is just as steadilv replaced by new material added to the hmd end of the ribbon.

Many shore animals, as we have seen, are attached to rocks or weed, or eise live in permanent tubes or burrows ; the advantage of these sheltered modes of life becomes clear when we consider the constant beating of the waves at varving height upon the shore. Of equal utility is the burrowing habit of some Urchins and bi-valve Shells, which also are able to move about beneath the surface.

Locomotion in litoral creatures takes many forms : the larger Crustaceans clamber over rocks and through gullies b y means of their strongly hinged walking-legs ; and Star-fish move steadily over these surfaces by the concerted action of many tiny tube-feet, * " N u m b e r s of Star-fishes, Uraster rubens, were washed ashore a t Gorleston d u r i n g s t r o n g east w i n d in first week of N o v e m b e r , 1901 " (Trans. N o r f o l k N a t . Soc. vii, p. 398).

A n incursion of Star-fish in 1906 e r a d i c a t e d a considerable bed of t h e mussei Volsella modiolus, Linn., n o r t h of t h e Bell B u o y , which h a d existed a few y e a r s before ; b u t in 1906 e m p t y v a l v e s alone were dredged b y s h r i m p - b o a t s a n d t h e Scoter D u c k s (CEdemia nigra, Linn.), whose feeding-ground t h e b e d h a d been, m o v e d t o s o u t h of G o r l e s t o n (lib. cit. viii, p . 4 6 4 ) . — E d .

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each terminated by a small sucker, double rows of such feet lining the grooves which run down the middle of the underside of each limb.

Throughout the surface of all Urchins' shells are little clawed spines of various patterns but usually having three teeth that can open and snap together ; they are very numerous in the splendid Clypeaster rosaceus, Linn., a West Indian species. These are used to clean the shell by removing any fragment of waste matter ; but also for protection : if an Urchin be attacked, the long spines upon the threatened side turn away, exposing the shorter clawed spines beneath, which snap at any part of the attacker, and also produce a poison that passes into the wounds thus caused. Surely we can but marvel at the wonderful provision Nature arranges, generally in the way of sustenance and of protection from extraneous assaults, a protection particularly specialised in the case of Sea-urchins.f

Appended is a preliminary List of Suffolk Echinodermata, so far as the species seem known by the very small amount of attention hitherto accorded these animals. Our sparse chalk outcrops preclude any approach to the abundance a t Birchington.

Collectors are Mr. C. G. Doughty ; the Rev. Graves Lombard ; Mr. Claude Morley; E. W. P l a t t e n ; Miss G. W a t s o n ; British Museum ; Ipswich Museum ; Aldeburgh Museum ; Peterborough Museum ; Thetford Museum (the Yarmouth and Norwich ones exhibit none from Suffolk) ; Norfolk Naturalists' Soc. Transactions ; Suffolk Naturalists' Soc. Transactions; and the County Victoria History.

Also Lowestoft Library possesses a few unnamed specimens from Corton and Hopton.

For the Classification, reference should be made to the Crag species of Forbes in the Palaeontographical Society's Memoirs and Wright's Monograph of British Fossil Echinoderma: Cretaceous i, Echinoidea, pp. 1-371 and pll. i-lxxx. No especial collecting has been attempted for this paper, which merely brings together those specimens that happen to be already in hand. f Folk lore is d i s t i n c t l y u n N a t u r a l H i s t o r y ; y e t we m a y v e n t u r e t o n o t e t h a t a good deal of it a t t a c h e s t o t h e fossil Echinoidea, locally t e r m e d Fairies' or Pharisees' L o a v e s .

I n t h e d e f u n c t E C o u n t i e s ' Magazine, i, 237, o n e a t H e p w o r t h , b e a r i n g a double-cross, is a s s e r t e d t o e n d o w its finder w i t h e x t r a o r d i n a r i l y good luck : I t will p r e s e r v e you f r o m t h e evil doings of t e m p e s t s ; if t h e discoverer be a m a n h e m a v e x p e c t a h e a p of gold, or if a w o m a n she m a y a n t i c i p a t e so good a h u s b a n d as will m a i n t a i n h e r w i t h o u t w o r k i n g for life.

E a c h Loaf is supposed lost b y a F a i r y , who r e d e e m s his p r o p e r t y m o s t generously ; t h o u g h , if i t be witheld f r o m him, disaster dogs t h e o w n e r ' s p a t h . — E D .

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Subkingdon RADIATA. Class ECHINODERMATA. Order ASTEROIDEA:

Star-fish.

Family OPHIURIDAE. Ophiura ciliaris, Linn. —Orwell-mouth (Vict. Hist.) ; Southwold, Felixstow, etc., not rare (Morley).

Ophiura albida, auct.—Common in Southwold fishing-boats (id. ; teste Tomlin).

Ophiothrix fragilis, Müll.—Sometimes abundant in the Orwell, and occasionally dredged at its mouth (Vict. Hist.) ; Southwold (Morley).

Synapta inhaerens, Müll.—Many in mud near low-water mark slightly below Pin Mill before 1900 (Vict. Hist.). A local species.

Family A S T E R I I D A E .

Uraster rubens, Linn.—" Hundreds of five-rayed Stars " were observed on 5th April 1902 after a gale from the N.E., on the beach north of Yarmouth (Trans. Norf. Soc. vii, p. 566) and, doubtless, south of it. Covehithe, Southwold, Dunwich, etc., abundant along our whole coast-line (Morley).

Solaster papposns, Fab.—In most estuaries, but nowhere abundant (Vict. Hist.). " Hundreds of eleven, twelve and thirteen-rayed Stars " were observed on 5th April 1902, after a N.E. gale, on the beach north of Yarmouth (Trans.

Norf. Soc. vii, p. 566) and, doubtless, south of it also ; half one of these Sun-stars is there said to have caused temporary tetanus in a cat. " Numbers of Starfishes, S. papposa, were washed ashore at Gorleston during strong east wind in first week of November, 1901 " (I.e., p. 398). Felixstow, Dunwich, etc. (Morley).

Order ECHINOIDEA

: Sea-urchins.

Family CIDARIDAE. Cidaris serrifera, Forb.—A single fossil spine found at Santon Downham (in Mus. Thetford).

Cidaris claviger, auct.—One fossil spine from Waldringfield (in Mus. Ipswich).

Cidaris sp.— One speeimen fossilised at Stonham Aspal (in Mus. Thetford).

Echinus miliaris, Müll.—Common in the Aide, during 1898 in the Orwell, and abundant in mouth of Stour (Vict. Hist.) ; Bawdsey Ferry commonly in 1898, and always present in Southwold fishing-boats (Morley).

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STAR-FISH AND SEA-URCHINS.

Echinus sphaera, Müll.—Felixstow in 1900 (teste Tomlin) and Bawdsey in 1929 (Morley).

Echinus Cotteaui, auct.—Found in fossil State in crag, Ramsholt and Iken (Ipswich Mus.).

Echinus Woodwardi, Desor.—Fossil at Iken and Sudbourn (Ipswich Museum).

Taken in Coralline crag, Sudbourn Park, 25th September, 1930 (Morley, teste Brit. Mus.).

Echinus Lyelli, Forb.—Fossil at Sutton and Iken (Ipswich Museum).

Echinus Lamarcki, Forb.—One from '* Coralline crag, Suffolk " (in Peterboro' Museum) ; Red Crag at ' New wäter-works well, Aldeburgh, December, 1903' (Aldeburgh Museum).

Temnechinus excavatus, Forb.—This " genus occurs in the Red and Coralline crag of Suffolk : Ramsholt " (Lyell, Stud.

Element. 166, flg.). One from " Coralline crag, Aldeborough, Suffolk " (Peterboro' Museum).

Temnechinus globosus, Forb.—Fossil at Ramsholt (Ipsw. Mus.).

Temnechinus melocactus, Forb.—Fossil at Waldringfield, Sutton and Ramsholt (Ipsw. Mus.).

Temnechinus turbinatus, Forb.'—Fossil at Sutton (Ipsw. Mus.).

Temnechinus Woodi, Agaz.—Fossil at both Ramsholt and Sutton (Ipsw. Mus.).

Family

CLYPEASTERIDAE.

Echinocyamus pusillus, Müll.—Fossil at Sutton (Ipsw. Mus.) ; yet exists as British.

Psammechinus sphaeroidalis, auct.—Fossil at Ramsholt and Sutton (Ipsw. Mus.).

Micrastercor-anguinum, Lesk.—Fossils common on stone-heaps in High Suffolk, in Boulder-clay derived in water from the Chalk.

Monks' Soham 1912, 1915, etc. (Morley) ; Gorleston and PDunwich, circa 1920 (Doughty) ; from chalk-pit in Fakenham (Thetford Mus.).

Micraster praecursor, Rowe.—Euston estate (Thetford Mus.) ; Brandonroad heath 1901, and Monks' Soham 1912-25 with the last species (Morley, teste Brit. Mus.).

Micraster Leskei, Desm.—Santon Downham (Thetford Mus.) ; Monks' Soham from chalk, rare (Morley).

Micraster cor-bovis, Forb.—Euston estate (in Thetford Museum).

Micraster spp —Three specimens in Rendlesham 1907 and 1911 ; Bromeswell heath 1909 ; Wickham Market Station 1915 ; Eyke 1902 ; Ampton 1888 ; and by Mr. Cecil Wright at Framlingham 1910 (Lombard) ; Monks' Soham stoneheaps (1930, Watson, and 1922, Morley) ; Gorleston, circa 1920 (Doughty) ; also three unlocalised specimens.

Holaster planus, Mant.—Rendlesham 1909 (Lombard) ; Brandonroad heath 1901, Brandon 1911 (Morley) ; Ling

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heath in Brandon, Santon Downham and Thetford warren (Mus. Thetf.) ; Gorleston, circa 1920 (Doughty); several in Monks' Soham on stone-heaps 1911-30 (Mrs. Morley).

Clypeaster Anglicus, Forb.-—The unique type, described in Yorks Phil. Soc., is from ' Coralline crag, Aldeburgh ' (Aldeburgh Museum).

Ananchytes ovata, Lesk.—Monks' Soham on stone-heap 1915 (Morley, teste Brit. Mus.).

Echinocorys scutata, Lesk.—Rendlesham rectory drive 1910, and garden 1907 and 1911 and 1918 ; Framlingham 1907, by Wright (Lombard) ; Claydon chalk-pit 1930 (Platten) ; Ashfield, dredged from pond, 1930 (Abbot) ; derived from chalk Monks' Soham 1912 (teste Brit. Mus.) and dug up in Haughley by Mr. Woods 1930 (Morley) ; Thetford (in Mus. Thetf.).

Var. elevata, Bryd, " Whorlows pit, Sudbury, Suffolk" (in Mus. Thetf.).

Also three unlocalised specimens.

Conulus subrotundus, Agaz.—Lakenheath (Thetford Museum).

Conulus albogalerus, Lesk.—Rendlesham 1911 (Lombard) ; Monks' Soham 1922, and in the crag at Ramsholt 1930 (Morley, teste Brit. Mus.).

Conulus spp.—" Sudbury district " and " Euston estate " (in Thetf. Museum).

Phymosoma spp.—Rare and derived from chalk, Monks' Soham 1912 and 1915 (Morley, teste Brit. Mus.) ; Euston estate (in Thetf. Mus.).

Family SPATANGIDAE. Spatangus regina, Gray.—Found fossil at Orford (Ipswich Museum).

Spatangus purpureus, Müll.—Fossil at Orford (Ipsw. Mus.) ; yet exists as British.

Diadema megastoma, auct.—Fossil at Waldringfield (Ipsw. Mus.).

Amphidotus echinus, auct.-—Fossil at Foxhall (Ipswich Mus.).

Echinocardium cordatum, Pen.—Trawled off Southwold 1929 (Trans. Suff. Nat. Soc. i, 70).

Order

HOLOTHUROIDEA.

Family THYONIDAE. Thyone fusus, Müll.—Single and somewhat small specimens in estuaries of both Orwell and Stour (Vict. Hist.).

Cucumaria sp.—A fairly fine Holothurian moderately common in the Stour off Parkeston about 1890 (Vict. Hist.) ; inadequately named.

Order None yet recorded.

SIPUNCULOIDEA.