Summary
The calcified body wall of an ophiuroid was investigated by a new method and compared with that of other echinoderms. The previous opinion that the epidermis of ophiuroid arm shields consists of a reduced syncytium continuous with the underlying dermis is incorrect. The epidermis is distinctly separated from the dermis by a basal layer and consists of (1) supporting cells which bear the cuticle, (2) ciliated cells (hitherto unknown and probably sensory), (3) gland cells, and (4) nerve cells with the basal nerve plexus. The overall structure of the epidermis is a three-dimensional tube system (marked by the basal lamina) which penetrates the dermal tissue of the scale's pore space and continues with nerve cords situated below the scale. This arrangement is unique in echinoderms.
The dermal sclerocytes largely conform with those of the echinoid Eucidaris. The mineral skeleton is produced intracellularly or intrasyncytially. Moreover, dermal sclerocytes were found to release extracellular microfibrils which have nothing to do with calcite deposition. The attachment of the cuticle to the dermis is achieved by means of epidermal coupling areas. Collagen fibers fasten the scale to the underlying connective tissue sheath. The supposed fibrocytes within this sheath resemble sclerocytes. Each collagen bundle is provided with a strand of nerve fibers which, in contrast to the basal nerve plexus, are naked. They are said to infuence the mechanical properties of the connective tissue.
Structures associated with cilia occur in cell types which normally lack a cilium. This finding suggests that most echinoderm cells are potentially monociliate.
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Abbreviations
- A :
-
apical shield
- asp :
-
secretory products
- B :
-
bacteria
- bb :
-
basal body
- bl :
-
basal lamina
- C :
-
ciliated cell
- ca :
-
coupling area
- ci :
-
cilium,
- cf :
-
collagen fibrils
- cs :
-
cell surface
- CTS :
-
connective tissue sheath
- cu i :
-
inner cuticular layer
- cu m :
-
middle cuticular layer
- dp :
-
distal processes (Sc)
- EC :
-
epineural canal
- G :
-
Golgi complex
- gv :
-
granular vesicle
- H :
-
haemal vessel
- hb :
-
homogeneous body
- hl :
-
horizontal lamina (Su)
- j :
-
cell junction
- L :
-
lateral shield
- le :
-
boundary layer (Sc)
- lo :
-
distal lobe (Su)
- M :
-
intervertebral muscle or its attachment
- m :
-
mitochondrium
- mf :
-
microfibrils
- mu :
-
mucus
- mv :
-
microvilli
- mvb :
-
multivesicular body
- N :
-
nerve cell
- n :
-
nucleus
- nf :
-
neurofibrils
- ng :
-
neurogranules
- nn :
-
naked neurofibrils
- O :
-
oral shield
- P :
-
tube foot
- Pc :
-
phagocyte
- pg :
-
pigment granules
- rl :
-
rootlet
- RN :
-
radial nerve
- RV :
-
radial vessel
- Sc :
-
sclerocyte
- sh :
-
cytoplasmic sheath (Sc)
- sj :
-
septate junction
- Su :
-
supporting cell
- sv :
-
secretory vesicle
- T :
-
calcite trabeculum
- V :
-
vertebral ossicle
- v :
-
vesicle (Su)
References
Burkhardt A, Hansmann W, Märkel K, Niemann H-J (1983) Mechanical design in spines of diadematoid echinoids. Zoomorphology 102:189–203
Cobb JLS, Stubbs TR (1981) The giant neurone system in ophiuroids. I. The general morphology of the radial nerve cords and circumoral nerve ring. Cell Tissue Res 219:197–207
Crise-Benson N, Benson SC (1979) Ultrastructure of collagen in sea urchin embryos. Wilhelm Roux's Archives 186:65–70
Gardiner SL, Rieger RM (1980) Rudimentary cilia in muscle cells of annelids and echinoderms. Cell Tissue Res 213:247–252
Gibbins JR, Tilney LG, Porter KR (1969) Microtubules in the formation and development of the primary mesenchyme in Arbacia punctulata. I. The distribution of microtubules. J Cell Biol 41:201–226
Heatfield BM, Travis DF (1975) Ultrastructural studies of regenerating spines of the sea urchin Strongylocentrotus purpuratus. I. Cell types without spherules. J Morphol 145:13–27 pls 1–11
Hidaka M, Takahashi K (1983) Fine structure and mechanical properties of the catch apparatus of the sea urchin spine, a collagenous connective tissue with muscle-like holding capacity. J exp Biol 103:1–14
Holland ND, Nealson KH (1978) The fine structure of the echinoderm cuticle and the subcuticular bacteria of echinoderms. Acta Zool (Stockh) 59:169–185
Hyman LH (1955) The invertebrates IV. Echinodermata McGraw-Hill Book Co, New York, 783 pp
Jangoux M (1984) Diseases of echinoderms. Helgol Meeresunters 37:207–216
Jefferies RPS (1980) Zur Fossilgeschichte des Ursprunges der Chordaten und der Echinodermen. Zool Jb Anat 103:285–353
Kniprath E (1974) Ultrastructure and growth of the sea urchin tooth. Calc Tiss Res 14:211–228
Kobayashi S (1971) Acid mucopolysaccharides in calcified tissues. Int Rev Cytol 30:257–371
Luft JH (1971) Ruthenium red and violet. I. Chemistry, purification, methods of use for electron microscopy and mechanisms of action. Anat Rec 171:347–368
Märkel K, Gorny P, Abraham K (1977) Microarchitecture of sea urchin teeth. Fortschr Zool 24:103–114
Märkel K, Röser U (1983a) The spine tissues in the echinoid Eucidaris tribuloides. Zoomorphology 103:25–41
Märkel K, Röser U (1983b) Calcite resorption in the spine of the echinoid Eucidaris tribuloides. Zoomorphology 103:43–58
Martínez JL (1976) Histologia y ultraestructura de la cuticula de los podios de Ophiothrix fragilis. Bol R Soc Española Hist Nat (Biol) 74:167–181
Martínez JL (1977a) Estructura y ultraestructura del epitelio de los podios de Ophiothrix fragilis. Biol R Soc Expañola Hist Nat (Biol) 75:275–301
Martínez JL (1977b) Histologia y ultraestructura del tejido conectivo de los podios de Ophiothrix fragilis. Bol R Soc Española Hist Nat (Biol) 75:303–313
Martínez JL (1977c) Ultraestructura del tejido nervioso podial de Ophiothrix fragilis. Bol R Soc Española Hist Nat (Biol) 75:315–333
Motokawa T (1983) Mechanical properties and structure of the spine-joint central ligament in the sea urchin, Diadema setosum. J Zool Lond 201:223–235
Nørrevang A, Wingstrand KG (1970) On the occurrence and structure of choanocyte-like cells in some echinoderms. Acta Zool (Stockh) 51:249–270
Pilkington JB (1969) The organization of skeletal tissues in the spines of Echinus esculentus. J Mar Biol Ass UK 49:857–877
Pucci-Minafra I, Fanara M, Minafra S (1980) Chemical and physical changes in the organic matrix of mineralized tissues from embryo to adult of Paracentrotus lividus. J Submicrosc Cytol 12:267–273
Smith JE (1965) Echinodermata. In: Bullock TH, Horridge GA (eds) Structure and function in the nervous system of invertebrates, Vol. II. Freeman and Co, San Francisco and London, pp 1519–1558
Stubbs TR, Cobb JLS (1981) The giant neurone system in ophiuroids. II. The hyponeural motor tracts. Cell Tissue Res 220:373–385
Travis DF, Francois CJ, Bonar LC, Glimcher MJ (1967) Comparative studies on the organic matrices of invertebrate mineralized tissues. J Ultrastruct Res 18:519–550
Weber W, Grosmann M (1977) Ultrastructure of the basiepithelial nerve plexus in the sea urchin, Centrostephanus longispinus. Cell Tissue Res 175:551–562
Wilkie IC (1978a) Nervously mediated change in the mechanical properties of a brittlestar ligament. Mar Behav Physiol 5:289–306
Wilkie IC (1978b) Arm autotomy in brittlestars. J Zool (Lond) 186:311–330
Wilkie IC (1978c) Functional morphology of the autotomy plane of the brittle star Ophiocomina nigra (Abdilgaard). Zoomorphologie 91:289–305
Wilkie IC (1979) The juxtaligamental cells of Ophiocomina nigra (Abdilgaard) and their possible role in the mechano-effector function of collageneous tissue. Cell Tissue Res 197:515–530
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Märkel, K., Röser, U. Comparative morphology of echinoderm calcified tissues: Histology and ultrastructure of ophiuroid scales (Echinodermata, Ophiuroida). Zoomorphology 105, 197–207 (1985). https://doi.org/10.1007/BF00312157
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DOI: https://doi.org/10.1007/BF00312157