@article {541,
	title = {A functional organization of dermal coelomic canals in Sipunculus nudus (Sipuncula) with a discussion of repiratory designs in _____ sipunculans},
	journal = {Invertebrate Zoology},
	volume = {114},
	number = {1},
	year = {1995},
	note = {ABSTRACT; S. N. IS A LARGE SIP. THAT BURROWS ACTIVELY IN COARSWE MARINE SANDS. THE BODY SURFACE IS FOLDED INTO APPROX. 30 LONGI. RIDGES THAT EXTEND ALONG THE LENGTH OF THE TRUNK AND INTROVERT. A DERMAL CANAL LIES BENEATH EACH OF THE RIDGES AND CIRCULATES COELOMIC FLUID AND HEMERYTHROCYTES TO WITHIN A FEW MICROMETERS OF THE BODY SURFACE. COELOMICFLUID ENTERS AND LEAVES THE DERMAL CANAL THRU PORES LEADING FROM THE TRUNK COELOM AND FLOWS UNIDIRECTIONALLY AT APPROXIMATELY 0.7 MM/SEC. FROM POST > ANTER. THE FLOW IS GENERATED BY CILIA ON PERITONEAL CELLS LINING THE CANALS. THE VOLUME OF THE CANALS IS APPROX. 8\% OF THE TOTAL COELOMIC VOL. WE SUGGEST THAT SIP. SPECIES FALL INTO 3 FUNCTIONAL CATAGORIES BASED ON THE BODY REGION OR REGIONS USED FOR ENVIRONMENTAL GAS EXCHANGE. "TENTACLE BREATHERS" SUCH AS SPECIES OF THEMISTE, BORE INTO ROCKS OR MICRO-OXIC SEDIMENTS AND EXTEND THEIR NUMEROUS TENTS. INTO THE WATER. DISSOLVED GASES ARE TRANSPORTED BETWEEN THE TENT. \& TRUNK COEL. CAVITIES VIA WELL DEVELOPED CONT. VESS.. "TENTACLE AND INTROVERT BREATHERS". SUCH AS SP. OF ASPIDO{\textquoteright}IDAE \& PHASCOLOSOMATIDAE, LODGE THE TRUNK BODY IN THE SUBSTRATUM AND EXTEND AN ELONGATED THIN WALLED INTROVERT AND TENTACLES INTO THE WATER. THEIR CONT.VESS. ARE USUALLY SIMPLE UNBRANCED TUBES. "INTEGUMENTARY BREATHERS", SUCH AS SIP.NUDUS AND OTHER SP. OF SIP{\textquoteright}IDAE, HAVE INTEG. SPECIALIZATIONS FOR GAS EXCHANGE ACROSS THE ENTIRE BODY SURFACE, BUT USUALLY SMALL TENTACLES AND OFTEN WEAKLY DEVELOPED CONT.VESS.. METHODS / RESULTS / DISCUSSION (1, 2, 3 ABOVE)},
	pages = {51-63},
	author = {Ruppert, E. E. and Rice, M. E.}
}
