海(hai)參的(de)內(nei)骨(gu)骼(ge)多(duo)不(bu)發(fa)達,變為須(xu)用顯(xian)(xian)微鏡才能看見的(de)許(xu)多(duo)微小石灰質骨(gu)片(pian)(pian)(pian)(pian)(pian)埋沒于外皮之下,數目一(yi)般(ban)都很多(duo)。觀察(cha)骨(gu)片(pian)(pian)(pian)(pian)(pian)應作些(xie)處理,最簡單的(de)方法是(shi)取一(yi)小片(pian)(pian)(pian)(pian)(pian)皮膚(fu),置于玻(bo)片(pian)(pian)(pian)(pian)(pian)上,然后(hou)滴1-2滴次(ci)氯(lv)酸(suan)鈉(na)溶(rong)液于皮膚(fu)上,1-2min,次(ci)氯(lv)酸(suan)鈉(na)溶(rong)液會(hui)把皮膚(fu)組織腐蝕掉,而剩(sheng)下骨(gu)片(pian)(pian)(pian)(pian)(pian),再加(jia)1-2滴蒸(zheng)餾水,蓋上蓋玻(bo)片(pian)(pian)(pian)(pian)(pian),置于顯(xian)(xian)微鏡之下便能觀察(cha)清楚。海(hai)參骨(gu)片(pian)(pian)(pian)(pian)(pian)形狀(zhuang)美麗而多(duo)變,是(shi)海(hai)參分類最重要的(de)依據,常見的(de)骨(gu)片(pian)(pian)(pian)(pian)(pian)有桌形體(ti)、扣(kou)狀(zhuang)體(ti)、桿狀(zhuang)體(ti)、穿孔板、花紋樣體(ti)、輪形體(ti)和錨形體(ti)等。海(hai)參骨(gu)片(pian)(pian)(pian)(pian)(pian)數量很多(duo),有人(ren)計(ji)算過(guo)1個丑(chou)海(hai)參有約2000萬(wan)個骨(gu)片(pian)(pian)(pian)(pian)(pian)。
海參咽部(bu)圍繞(rao)一環鈣質骨(gu)板(ban),稱(cheng)(cheng)為石灰(hui)環,由10塊(kuai)骨(gu)板(ban)組成(cheng),5個(ge)(ge)輻位(wei)的(de)骨(gu)板(ban),稱(cheng)(cheng)輻片(pian),5個(ge)(ge)間輻位(wei)的(de)骨(gu)板(ban),稱(cheng)(cheng)間輻片(pian)。石灰(hui)環是(shi)海參特(te)有的(de)器(qi)官,它可能和海膽的(de)亞(ya)里斯多德提(ti)燈同(tong)源。石灰(hui)環形態(tai)在海參分類(lei)上也(ye)很(hen)重要。