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OSSICLES
by
Claude MASSIN
PEET Workshop
Brussels 04-08 December 2006
OSSICLES
• First drawing: Strussenfelt, 1765• Identified as such Lesson, 1830 (anchor)• used for taxonomy since 1860 • Change with growth: increase in size,
diminish in size, disappear, become more spiny, change of shape
• Neopentadactyla mixta: tables with 2 pillars tables with 4 pillars
OSSICLES
• Change with growth: increase in size, diminish in size, disappear, become more spiny, change of shape
• Neopentadactyla mixta: tables with 2 pillars tables with 4 pillars
• Pearsonthuria graeffei
OSSICLES
• Change with growth: increase in size, diminish in size, disappear, become more spiny, change of shape
• Neopentadactyla mixta: tables with 2 pillars tables with 4 pillars
• Pearsonthuria graeffei
• Heterocucumis steineni
OSSICLES
• Change with growth: increase in size, diminish in size, disappear, become more spiny, change of shape
• Neopentadactyla mixta: tables with 2 pillars tables with 4 pillars
• Pearsonthuria graeffei• Heterocucumis steineni • Change between juveniles and sub-adults 1mm to 20-
30mm• Afrocucumis straki
Tables:1 pillar ending in one or several points; disc with many peripheralholes (Synallactid like)
or 1 pillar ending in several hooks, disk without peripheral holes(Molpadid like)
2 pillars ending each in one or several points or fused in a singlepoint, or forming a small crown of spines, disc circular orelongated and arched (Dendrochirotid like)
3 pillars ending in a crown of spine or not (synallactids,aspidochirotids, dendrochirotids)
Tables4 pillars ending in a crownof spines or not (dendrochirotids, aspidochirotids) with thefollowing subcategories:
- Disc rounded or cruciform (Synallactid like)- (H. kurti: 25-35 mm; H. altimensis: 7-9 mm)
- Edge of the disc smooth, knobbed or spiny- Disc without peripheral holes, with few
peripheral holes or with numerous peripheral holes- H/W of the table>>1; = 1; <1
- Pillars ending in a crown of spines narrower,equal or larger than the disc
Tables- Crown of spines with a large central opening, a small
central opening or several central openings- Crown of spines forming a circle or forming a Maltese
cross- Pillars fused, smooth and endingin a single point or spiny and endingin several points (Stichopus, Holothuria)
- Disc of the table reduced or absent(Halodeima) disc of the table welldeveloped
- 5 pillars or more (Holothuria (Metriatyla); Eostichopus)
- Table transformed in fenestrated sphere
Pseudo tables
Rocket like table ofPearsonothuria graeffei
Pseudo-tables ofThelenota spp
Pseudo-tables of Cladolabes
New names are to be found for these ossicles
Buttons2 -10 pairs of holes with samediameter on two rows; no single hole at the extremities (angleof growth 90°), with or without a median longitudinal ridge
Smooth, knobbed or transformed in ellipsoids
PseudobuttonsAs a button but with a single row of holes, a second row with 1-2 holes can bepresent; often irregular and twisted
Perforated plates
Rounded- Tube feet end plate madeof one piece or several pieces
- Table reduced to the disc- - Lenticular perforated plate with or without eccentric spire
Baskets: small (4 holes), more or less arched perforated plate with or without a cross beam, smooth or knobbed (dendrochirotids )
Perforated platesElongated- Derived from buttons(all the holes with same diameter)
or derived from perforated rods (central holes larger than peripheral holes), with or without a median longitudinal ridge
- Racket shape with handlesmooth (molpadids)
or spiny (dendrochirotids)
Derived from 2 dimensionalbranched rods (Stichopus, Thelenota)
Rods
- Simple, rarely bifurcated, spiny or smooth,straight or curved, without holes (cf tentaclerods of many aspidochirotids)
- - Two dimensional large branchedrods, spiny (Stichopus, Thelenota)- or three dimensional branched rods,smooth or spiny (most of the elasipodids)
- Perforated rods (at the extremities and or alongthe axes) (Holothuria) with or without amedian longitudinal ridge
Rods- Rods non perforated atthe extremities but withspiny lateral processesand/or a central perforatedprocess (Stichopus)
- Massive perforated rods(at the extremities and/oralong the edges) smooth or spiny(Selenkothuria)
- Small rods fromActinopyga sppand Bohaschia spp
RodsC-shape rods regular or irregular (irregular looklike rosettes)- from Stichopus
- from ApodidsChiridota(slender or thick)
- from Holothuria longitudinal muscle
- from Stichothuria
S-shape ossicles from Stichopus
GranulesSpherical or contorted, non perforatedmaximum 10 µm long (Thelenota)
Miliary granules- Spherical, ovoid or elongated ossicles made of tri-dimensional branched rodscovered by numerous granules(Dendrochirotids; apodids?)- U-shape ossicles with onerow of external granules (apodids)
GrainsSpherical or elongated ,non perforated ossicles minimum 15 µm across (Bohadschia)
Elongated or irregular with 1-3 holes
(Bohadschia)
RosettesSmall branched rods (angle of growth 120°) with rounded extremities more or less plump (Actinopya,Bohadschia,Stichopus, dendrochirotids)
Branches of the rods may fuse giving rise to smallperforated plate (4 holes: 2 large and 2 small atthe extremities)(Halodeima)
Pearsonothuria graeffei
Between grains, rosettes and rods all intermediary stages
Anchors, anchors plates, wheels , hooks or sigmoid rods
QUESTIONS
• What is a pseudo table?
• What is a rosette?
• What is a grain, granule, miliary granule?
• What is a C-shape rod?
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