Part V.-Crustaceans, Worms, Radiates, and Sponges
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SEC']~ION I. PART V.-CRUSTACEANS, WORMS, RADIATES, AND SPONGES. By RICHARD RATHBUN, 759 ANALYSIS. Y.-CRUSTACEANS: Ptt.ge, 221. The CrabB .... -. -........• __ .. ..... _..•.._.. __ ..... _. '" __ .. __ .•••••..•...•••. .. .. 763 22:!, Ttf! Common Edible or Blue Crab .. __ .. _. __ •_.••. _.•••. ••..• ..__ •.•.•• __ ••.•••_.•••••. __ ._ 775 22:1, Tbe LobBters ,_, .•••.. _. __ .. _.. __ _. _ _ _ _. '" _•.•_•••.•••_••.• _ it\O 2'M, The American Lobster. _ __ " _.•..• _. .. 781 2i!5. Th" Cl"l1~' FiBLe~, AstacuB and CambaruB _ "" _ _...••.. 812 2il6. The Shrimpll and Pr3.Wllil • _••.•••••• __ ••••••••••••••••••••••••• _ •••••••• _ ••• _. _ •• _ "" •••• ' 'J16 227. The Mantis ShrimpB; S'luillid _"'''' . _•.•. _.....•. _. _ __ _ 82:l 228. The AIIll'bipods __ ...•.......•............................,_ "" .•_ _ 8'24 2".t9. The IsopodB .. __ .' __..•... , .•................... _..... _•.••....• _._ . ....•....... "" .. __ . _ 1t2G :130. The EntomostracanB _",., __ ...••......•....... _ _.. _......••.•.••......._. 827' ~:n. The Ci'Tipeclia _. '" _ __ __ __ .. __ __ •... _ """ _. d'28 232. The XiphOBura __ _ _..• __ _.. _.. _ ___....•.. .._. _ .. _.. _.. _ 8'J9 Z.-\YOR:lf8: 23:\. The AnnelidB .•.•........ _ _. __ _...•.._......•...... _..••••..•_.. ._ _ 831 234. The LeecheB_ .•• ""'" _. _••...••..•.•... .. .•..••.•_ _.' _ _ H3.1 Z. A.-TIII~ RAOIATES: 23,,",. The Echiuo.lermB _••..•...•••.•.... """ _ •.••••.••• ,_, _. 838 236. The CrlenterateB ..•. _. ..••••.•• _• • .. __ • _.••._••_ .. __ ••.••••.....•...•...•••.... 841 Z. n.~THE FOlla'ERs: 237. ThllSpOllges••.•••••••••••.. __ ._. _. __ ••••••••.•••_. _._ •••••••••• •••••••••• _•.•••••••• - ..•-_ •. 843 238. TbII Genus 8poogia, and the American Commercial 8pongee•••••_••••••••• __ ••••••••__ •• _.•.•_••. 84 6 239. Injurious SpongeB .•••••..•.•••••••••••••••••••••••••• __ •••_•••••••• • "'_" . _•.••••••. -- 850 (761) Y.-OR UST ACEANS. 221. THE CRABS. THE FIDDLER CRAlIS-GELAsnIUS PUG;:;JAX, Smith; GELAiH'ilfUS PUGILATUR, Latreille; GELASI .:lILTS MI"NAX, Lc COllte. Thr('e 8))eOie8 (If Vidl1ler Urabs oeeUf upon tIJI< Atlantic coast of th(> IT nited Sta.tel;1, and nre frequently utilized as bait. Cong-regatiu~ tQgethcr ill immeu"e number", a" tb{·y often do, and excavating their holes generally in eonvenient localities, above the read. of the t.id{'s, they lllig'llt be easily collectclt ill large (]ualltities, WCfC til",)' IW1te1' a]lJln~eillt",d h.v tile fishel'mCll. Must dwellers upon the sea-shorf' are acquainted with that IH·(~n1iarit.~' 01" Hw ]"iddlt·r Urahs which lias ginm to them their common name, amI by which tllcr are H'adil.\· dif;tilll(ui8lted from our nth"r Crabs. The mal,'s lIre pnwi{led with two vl:'ry uneqnal elaws, one heillg of large, the other of quite "mall size, in comparison with lhe size of the animal. Of thl'se, the larg'l·.r etaw llll~ heel! likened to a fiddI(1 }1Tl(I the !'llllaller one to a how ; h'lIIe!' til(> dt'rivatioll of 111(' nanlf'. 'l'hc ('laws of the feuiales are, however, of {'qual alHl small size. The thr('-(\, species mentioned as !lving upon tho Atlantk tlOast a.nl OewHimU8 lIIinax, G. pugna.r, and O. pugilatnr. 'rhe former i'l'ede1:i, 'wllieh is 1he lal'gf'i't, ranj,!,l'S t"1'Olll the sourheru (~oast. df 1"ew Englaud to Floridu, ami lin's llPOll l:\alt llHlr8hel:l, lll>uli.lly fartller fl'OUI I!w Sf-a than the ot.hers, and frl'qnclltly wlwre the water is Twarl.Y frc.'1h. U. ptl{1na.r ra1t~('8 from Capo Uwl t,o Florida, and al.~o oceurs ill tIl(' Gulf uf :\-fl'xieo ~\I'<1 ~'1Il0l1~ til(' \V"sl Im!iEIS. "It HW.kes it!:! burrows only Il}lOIl salt marsh!'!;, hut is oftell seell ill gn'nt COlllllalliel> wal:th'l'illg Oil! uJlon lnmld) or sandy fiats, or e...en npon the ~Hches of the bays amI Rounds." G. pttf7i1ator rallge~ from Cape Cod to Florida, upon muddy fllld ~alld:v flat!'; and 11f':lPbt'~. l'ro1'el'ROr Verrill de1'1('rilw~ thl' hnhits and characteristics of these species as ioHoWf;: I .. We find several species of Crabs burrowing in mnddy bank!! a,long the shores of tlle estuaries, liS well as along hanks of thf\ 8tl'l~ams ulld ditches of the Slllt mar"IH'8. Till' most abundant of these is the m~u8h Fiddler Crab, Gdasimu8 jJ'Uonax, wbich is often so ahmul:.:llf, that the banks are completely houe.\'(:omb('d \'lud undermilled h.y them. Th('se holes are of ....Hious sizes up to about three·quarters of a,tl ineh in diameter, and descend more or lp!\s perpenditlUln.rl.,·, often to the depth of two feet or more. Ocoosionally in summer these Crahs wiII lea'~e thl'ir holes and scatter over the surface of the marshes, which at times seem to be perfectly alin~ with them, but when distnrbtod they will scamper a,way in e,,"erj direction and speedi1;\, retreat to their !.:loles; bnt ocCasiou...IIy, at least, they do not find their OWll, for sometimes the rightful owner will bB seen fon1bI;r I"Jecting several intruders. It is probable that at such times of general retreat each one get.s i!lto .theJlrst hole that he can find. Associated with tbis ':Fidctler,' allother relau-d Crab, tlll~ flesarma mucalRta, is ocCHBionall,v found in con",jdcrable nnmbers. This is a stout-looking, reddish brown crab.,witb a squarish cllrapax; its large claws are {ltont and ncarl,)' equal ill both sexes, , iU8tt".adof being very unequal, as in the male 'Fiddlt"r~.' It Jives in boles like the 'Fiddlers,' ,1 ~rt upon the Invertebrate Animals of Vineyard Sonnd, etc., In. Report United Staws Fish Commissioner for lFl71-''72,.pp. 836, 466. ' 764 NATURAL HISTORY OF AQUATIC ANIMALS. but it.8 holes are usually much larger, often an inch or an inch and a half in diameter. It is much less active than the' Fiuulers,l bnt can pinch very powerfully with its large. claws, which are always llromptly llsed when all opportunHy occnrs. "On the man;hes farther np the {'stuaries, nml along the mouths of river!'! and brook8, am} extending up even to places where tile walel' is quite fresh, another and mueh larger spNlit's of 'Fiddler Orab' occurs, oftEm ill alHllldallee; this is tll(\ Gelasimulf 'IIlinM!. It ean be easily, distinguished by its mndl larger size and h.y haVing a. Jlah~h of r~d at t,lle joints of the legs. Its halntf; baNe been carefnlly stndied by Mr. T. M. Prutlden, of New Haven, who has also investigatel} itl:! aIllttomy. According to .I\1r. Prudden, this speeies, like (}elasimuE pugilator, is a vegetarian. iIe often saw it eIlgagcd ill scrapiu~ up and cHting a milJUte green algoid plant which covers the surface of the mud. The male uses its small etaw eXdusively in obtaining its food and c(Hl\'eying it to tlJe mouth. The female uses eituer of' her small ones indifferently. In enlarging its burrows, Mr. Prutluen observed that these Crabs scraped oft' the mud from theiuside of tho hurrow b;v means of the cla,ws of the ambulatory legs, and: having formed the mud into a pellet, push('d it, up out of the hole by means of the elbow.likejoint at the base of the great claw, when this is folded down. He also ascertaiued that this Crab often constructs a regular oven-like arch of mud over the mouth of its burrow. This a,rchway is horizontal, and Ia.rge and long enongh 10 contain t1w Crab, who quiet,ly sits in this curious doorway on the lookout for his enemies of all kinds. "This species can live out of water and without food for mallY day!>, It. can lll!<o live in perfectl~T fre!<h water. One large mAle was kept. ill Illy laboratory in a glass jar, containiug llOthilig but a little 8iliceous sand moil>tened with pure, fn>sh water, for over six months. During- this whole period be seemed to be eonstantly in motion. wlllking rOUD d aod round t he jar a uti t r.yin g to climb out. He was never observetl to rest or apIH'l1l' tin>d, and after months of confinementand starvlttion waH jU8t as llUgnaciouH a'" en'l'. "Although some of the coloni{~s of this spades live nearly or quite IlII to ff('sh water, others are found t'arthe,r down on the m~ushes, where the water is quite bracliish, and tIlllS there is a middle ground where thiR allll G. pugnarc occur together. This was found by Mr. Pru{ldelJ to he the caJ,le both on the marshes bordering West River !lnd on those of Mill Rivl'r, near New llavl'n. They are abundant along both theMe streams. The holes ma{!{1 hy t,his "pedes are much lurger than those of G. pllgrul.r, Some of them are from an irlch and a half to two inches; !n dialnl'tl'r, "On sandy beaclu:'s near higl.J~wat{'r mark, especially where tIlt', sanel i~ rHtht.>r llOmpllot ami somewhat slleltered, oue oi the' Fiddler Cl'ahOl,' Gelasimu.s pUlIilaffJT, j~ freqnentl;\' foutHl ill gl't'at nnmbel'!:'1 1 either running act,h'ely about over the sawl, or peering el1utiouRly from their holes, which are often thickly scattered over considerable areas. The!!e hoh~s ftTI\ mustl.v from Iwlf all inch to an inch in diameter, and a foot or more in depth, the upper part nearly perpemlieular, becoming horizontal below, with a chamber at the end.