Diadema savignyi

Michelin, 1845

沙氏冠海膽（又名藍環冠海膽）

Size：36mm

Family：Diadematidae冠海膽科

Locality：台東都壢, Taiwan

Diadema savignyi 沙氏冠海膽 aboral view.

Diadema savignyi 沙氏冠海膽 aboral view. close-up.

Diadema savignyi 沙氏冠海膽 oral view. close-up.

Diadema savignyi 沙氏冠海膽 Lateral view.

Diadema savignyi 沙氏冠海膽 Lateral view. close-up.

Temnopleurus toreumaticus

(Leske, 1778)

細雕刻肋海膽

Size：29.3x15.7 mm

Family：Temnopleuridae刻肋海膽科

Locality：Tonggong, Taiwan

Test體殼：體型小，體殼直徑約4~5公分，最大6公分。體殼堅固，側面形狀變異甚大，從低矮的半圓球形到高的圓錐形都有；其棘的顏色變化也很大，很難讓人相信是屬於同一種。

Apical system(頂系)：屬dicyclic type，肛門偏離肛圍的中點，約偏離半徑的一半。些許往上突出，生殖板內部佈滿小疣環繞著肛圍，外部則無任何小疣，而眼板則密佈小疣。肛圍由許多小骨板堆疊而成。篩板上佈滿甚多小篩孔。

Ambulacra(步帶區)：步帶區寬約為間步帶區寬度的2/3，3個管足對孔形成明顯的對孔弧，步帶板上下有明顯下凹的溝，步帶縫合線兩邊的步帶板溝呈交錯分佈。步帶板有一排列規則的齒狀大疣。

Interambulacra(間步帶區)：間步帶板有一排列規則的齒狀大疣居中，每一間步帶板下方有一深陷的凹槽，在大疣附近最寬廣，而間步帶縫合線兩邊的間步帶板溝呈交錯分佈而不融合。約有數個小疣呈弧狀分佈在齒狀大疣上方。

Peristome口圍：口圍明顯凹陷，腮膜裸露，buccal notch淺而不顯著，直徑約為口面直徑的1/3-1/4。

Spine棘刺：棘短而細，不超過體殼直徑的1/4。棘的顏色有褐色與白色。

Color顏色：活體呈暗橄欖色，裸殼為灰橄欖色。

Biology生物特性：分布於0~82公尺深的泥沙底海域。本種是雜食性海膽，通常食碎屑為主。

Distribution分佈：是印度-西太平洋區最普遍的海膽，也是中國大陸分布最廣的海膽種類。廣泛分布於印度-西太平洋海域；是中國大陸各海域的廣佈種，台灣海峽偶而可見，但以金門和馬祖海域較常見，常成群棲息。

參考資料：

1. Sea Urchin  P174

2. 自然與人文數位博物館 -棘皮動物典藏知識單元

http://emuseap.nmns.edu.tw/DigiMuse/NewModule.aspx?ObjectId=0b000001800322b0&ParentID=0b000001800322b0

Temnopleurus toreumaticus 細雕刻肋海膽 aboral view.

Temnopleurus toreumaticus 細雕刻肋海膽 olique-aboral view.

Temnopleurus toreumaticus 細雕刻肋海膽 lateral view, ambulacral & interambulacral zone.

Temnopleurus toreumaticus 細雕刻肋海膽 lateral view, ambulacral & interambulacral zone.

Temnopleurus toreumaticus 細雕刻肋海膽 lateral view, ambulacral zone.

Temnopleurus toreumaticus 細雕刻肋海膽 lateral view, interambulacral zone.

Temnopleurus toreumaticus 細雕刻肋海膽 oral view.

Temnopleurus toreumaticus 細雕刻肋海膽 oral view, close-up.

Temnopleurus reevesi 芮氏刻肋海膽,
Camarodont type Aristotle's Lantern,
lateral view with various different degree.

Temnopleurus reevesi 芮氏刻肋海膽 , Aristotle's Lantern, apical view.

Temnopleurus reevesi 芮氏刻肋海膽 , Aristotle's Lantern, oral view.

Temnopleurus reevesi 芮氏刻肋海膽,
Aristotle's Lantern within test, peristomal membrane partial rupture,
view with various different degree.

Temnopleurus reevesi 芮氏刻肋海膽 , aboral view.

Temnopleurus reevesi 芮氏刻肋海膽 , aboral view, apical disc, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view, close-up, with Arithtotle's Lamtern and peristomal membrane.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view, close-up, remove Arithtotle's Lamtern and residual peristomal membrane.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view with flash light, , remove Arithtotle's Lamtern and residual peristomal membrane.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, ambulacral area.

Temnopleurus reevesi 芮氏刻肋海膽 , olique-lateral view, ambulacral area.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, interambulacral area.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, interambulacral area, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , oblique-lateral view, interambulacral area, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, ambulacral and interambulacral area, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , aboral view.

Temnopleurus reevesi 芮氏刻肋海膽 , aboral view, apical disc, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, ambulacral area.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, interambulacral area.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, interambulacral area, close-up
.

Temnopleurus  reevesii

(Gray, 1855)

芮氏刻肋海膽

Size：44mm

Family：Temnopleuridae刻肋海膽科

Locality： Penghu Is, Taiwan

 

 

Test體殼：體型小，體殼直徑約2~4.7公分，殼高約2公分。半圓球形到低矮扁平圓錐形都有。

 

Apical system(頂系)：屬dicyclic type，肛門係為強遠心型，即偏離肛圍中點，非常接近肛圍的外圍。肛圍由許多無小疣的小骨板堆疊而成，suranal plate非常顯著並有數個小疣。生殖板內部佈滿小疣環繞著肛圍，外部則無任何小疣，而眼板則佈有一些小疣，眼孔上方多少有些許往上隆起突出。篩板上篩孔不甚明顯。

 

Ambulacra(步帶區)：每塊步帶板上有1枚大疣位於中點與1枚中疣位於縫合線旁，疣帶有不甚明顯的齒。管足對孔幾乎排成一縱行，每3個管足對孔形成明顯的對孔弧。步帶板上下有明顯下凹的溝。步帶縫合線兩邊的步帶板呈交錯分佈，並有清析可見的接合凹洞。步帶區寬約為間步帶區寬度的2/3。

 

Interambulacra(間步帶區)：每塊間步帶板在赤道部有1枚齒狀大疣居中，左右各有1枚齒狀中疣在旁，規則排成一橫行。間步帶縫合線兩邊的間步帶板呈交錯分佈，並有清析可見的接合凹洞，其對面有一小疣亦沿著呈間步帶縫合線兩邊交錯分佈。間步帶板與步帶板的縫合線也有清析可見的接合凹洞。

 

Peristome口圍：口圍明顯凹陷，腮膜裸露，buccal notch不顯著，直徑約為口面直徑的1/3-1/4。

 

Spine棘刺：赤道部的大棘長度約為殼徑的1/2~2/3，棘細長的末端沒有變細，而是切平。反口面的棘一般為淺綠褐色，口面的棘色淺或帶淺綠色。

 

Aristotle's Lantern：Camarodont type

 

Color顏色：活體帶黃綠色調，裸殼為淡橄欖綠並帶點黑褐色斑，間步帶板與步帶板的大疣內部顏色較黑，形成一不規模黑褐色帶狀。

 

Biology生物特性：本種是雜食性的海膽，以有機底泥、藻類碎片、小型底棲性無脊椎動物及動物屍體為食。生活於5~565公尺深的泥沙底，

 

Distribution分佈：廣泛分布於印度-西太平洋海域(東非、日本南部、中國南海、菲律賓及印尼)，是中國大陸東海及南海常見的種類；也是台灣海峽北部泥沙海底最常見的一種海膽。東北角海域也常見，在宜蘭大溪漁市場的下雜魚堆中常可採獲。

 

參考資料：

1. Sea Urchin  P172

2. 自然與人文數位博物館 -棘皮動物典藏知識單元

http://digimuse.nmns.edu.tw/DigiMuse/NewModule.aspx?ObjectId=0b000001800322ac&ParentID=0b000001800322ab&Domin=z&Field=s0&Language=CHI

 

Temnopleurus reevesi 芮氏刻肋海膽 , aboral view.

Temnopleurus reevesi 芮氏刻肋海膽 , aboral view, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view.

Temnopleurus reevesi 芮氏刻肋海膽 , oral view, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, close-up.



Temnopleurus reevesi 芮氏刻肋海膽 , lateral view.

Temnopleurus reevesi 芮氏刻肋海膽 , lateral view, close-up.

Temnopleurus reevesi 芮氏刻肋海膽 , spines, Maximun:30mm up.

Temnopleurus reevesi 芮氏刻肋海膽 , spines, close-up.

Salmacis belli

Doederlein, 1902

貝利角孔海膽

SIZE：78X 50.2mm

FAMILY：Temnopleuridae刻肋海膽科

LOCALITY：Penghue Is. , Taiwan .

感謝 “(自戀)”兄慷慨贈送此顆海膽以資比對「Salmacis bicolor L. Agassiz, 1846 雙色角孔海膽」的迷惑，基本上此兩顆海膽如經過清洗後的殼體自有其相異之處，但當牠還是活體或還是有棘刺存在的標本時，外觀相似度極高，即這兩者的棘刺都是黃綠色片段與紫紅色片段相間。但經比對其棘刺卻有極大的不同，棘刺最主要的差別在基部顏色的差異，belli是綠色而bicolor是赭紅色。

Salmacis belli, aboral  view.

Salmacis belli, Apical system.

Salmacis belli, lateral view. ambulacrum area.

Salmacis belli, lateral view. ambulacrum area. close-up.

Salmacis belli, lateral view. ambulacrum area. more close-up.

Salmacis belli, lateral view. interambulacrum area.

Salmacis belli, lateral view. interambulacrum area. close-up.

Salmacis belli, oral view.

Salmacis belli, oral view. close-up.

Salmacis belli, oral view. more close-up and perignathic girdle.

Salmacis belli, oral view. perignathic girdle.

Salmacis belli, primary spines and secondary spines.
The longest spine measured about 16mm.
.

Salmacis belli, primary spines spines. close-up.
greenwish base of neck and collar area of spine.
and the shaft is red to purple segment alternating with dark green segment.

Salmacis belli, primary spines and secondary spines. close-up.
some spine are flatten and only green/yellowish color with a red segment .

Salmacis bicolor

L. Agassiz, 1846

雙色角孔海膽

SIZE：57x 35.6mm

FAMILY：Temnopleuridae刻肋海膽科

LOCALITY：Penghue Is, Taiwan

Salmacis bicolor , aboral view.

Salmacis bicolor , aboral view. close-up.

Salmacis bicolor , lateral view.

Salmacis bicolor , lateral view. ambulacrum, close-up

Salmacis bicolor , lateral view. ambital ambulacrum , more close-up

Salmacis bicolor , lateral view. interambulacrum .

Salmacis bicolor , lateral view. interambulacrum . close-up.

Salmacis bicolor , lateral view. ambital interambulacrum . close-up.

Salmacis bicolor , oral view.

Salmacis bicolor , oral view. close-up.

Salmacis bicolor , Aristotle's Lantern, lateral view.
Camarodont type

Salmacis bicolor , Aristotle's Lantern, lateral view.

Salmacis bicolor , Aristotle's Lantern, aboral view.

Salmacis bicolor , Aristotle's Lantern, oral view.

Salmacis bicolor

L. Agassiz, 1846

雙色角孔海膽

SIZE：57x 35.6mm

FAMILY：Temnopleuridae刻肋海膽科

LOCALITY：Penghue Is, Taiwan

Salmacis bicolor , aboral view.

Salmacis bicolor , aboral view. apical system.

Salmacis bicolor , aboral view. interambulacral area.

Salmacis bicolor , aboral view. ambulacral area.

Salmacis bicolor , oral view.

Salmacis bicolor , oral view. close-up 

Salmacis bicolor , oral view. more close-up 

Salmacis bicolor , lateral view.  interambulacral area. 

Salmacis bicolor , lateral view.  ambulacral area. 

Salmacis bicolor , lateral view.  ambitus area. cluster spines and longer spines. 

Salmacis bicolor , lateral view.  ambitus area. some longer whitish secondary spines also noted. 

Salmacis bicolor 雙色角孔海膽 的大棘，
基底部為赭紅色為特色，
間以黃色--紫色片段為主幹。

Salmacis bicolor , lateral view.  cluster of primary and secondary spines . 

Salmacis bicolor , primary spine. 

英國自然歷史博物館(The Natural History Museum)針對Temnopleuridae刻肋海膽科之Salmacis屬的診斷特徵，列出以下9點特性以供參考：

Salmacis L. Agassiz, 1841, 

Diagnostic Features：

• Test hemispherical to subconical in profile; ambitus relatively low; oral side relatively flat.

• Apical disc dicyclic, with distinct ring of tubercles surrounding periproct. Periproct subcircular; no enlarged suranal plate in adults.
  

• Ambulacral plating trigeminate with pore-pairs in oblique rows forming a single irregular adradial band; a few tubercles occur in amongst the pore-pairs. Plate compounding echinid-style. Each plate with a larger adradial primary tubercle and a usually smaller perradial secondary tubercle plus scattered miliaries.
   

• Interambulacral plates elongate with primary tubercle usually distinct, flanked on either side by only slightly smaller tubercles, forming a row of up to 5 subequal tubercles. remainder of plate rahter naked with only sparse miliaries.
  

• All tubercles imperforate and crenulate; ambulacral and interambulacral tubercles of similar size.
   

• Well defined sutural pits at all triple junctions; horizontal tubercles only very exceptionally (S. belli) with small pits.
  

• Peristome small with no effective buccal notches.
  

• Spines short and simple.

• Lantern camarodont.

Distribution：Recent; Indo-West Pacific

Type：Salmacis bicolor Agassiz, in Agassiz & Desor, 1846, by original designation

Species Included：

• S. bicolor (Agassiz, in Agassiz & Desor, 1846); Recent, Indo-West Pacific.
  
• S. belli Doderlein, 1902; Recent, Malay archipelago.
  
• S. roseoviridis Koehler, 1927; Recent, Indian Ocean.
  
• S. sphaeroides (Linnaeus, 1758); Recent, Indo-West Pacific.
  
• S. virgulata Agassiz, in Agassiz & Desor, 1846; Recent, Indian Ocean.

Classification and/or Status：Euechinoidea; Camarodonta; Temnopleuroida; Temnopleuridae.

Remarks：Very like Temnopleurus but with only small angular pits confined to suture triple points.

Cidaridae頭帕科 - Stylocidaris屬的診斷特徵

英國自然歷史博物館(The Natural History Museum)針對Cidaridae頭帕科之Stylocidaris屬的診斷特徵，列出以下8點特性以供參考：

Stylocidaris    Mortensen, 1909

Diagnostic Features：

• 
  
  Test moderately thick.

• 
  
  Apical disc about 50% of test diameter;

generally monocyclic with oculars narrowly insert. Genital plates all similar in size; apical disc plates uniformly covered in tubercles.

• 
  
  Interambulacra with 6-8 plates in a series.

Primary tubercle perforate, non-crenulate or weakly subcrenulate adapically; areoles circular and incised; widely separated.

• 
  
  Scrobicular tubercles not much differentiated. Extrascrobicular zones small and densely covered in heterogeneous secondary tubercles and granules.

• 
  
  Interradial and perradial sutures weakly incised.

• 
  
  Ambulacral zones weakly sinuous. Pore- zones a little incised; pore-pairs non-conjugate. Perradial zone with marginal series of contiguous primary tubercles plus much smaller inner series.

• 
  
  Peristome smaller than apical disc. Ambulacral plates uniserial in each column; interambulacral series reaching the mouth.

• 
  
  Primary spines weakly fusiform and slender; neck and collar short; shaft ornamented by beaded or serrated ribs.

Distribution：Miocene to Recent, widespread

Species Included：

• S. affinis (Philippi, 1845); Recent, Mediterranean, Atlantic, Caribbean.
  
• S. lineata Mortensen, 1910; Recent, Caribbean.
  
• S. reini (Doderlein, 1887); Recent, Indo-West Pacific.
  
• S. amboinae Mortensen; Recent, Indo-West Pacific.
  
• S. annulosa Mortensen, 1927; Recent, Philippines.
  
• S. conferta (Clark, 1916); Recent, Australia.
  
• S. rufa Mortensen, 1928; Recent, Hawaii.
  
• S. calacantha (Agassiz & Clark, 1907); Recent, Hawaii.
  
• S. bracteata (Agassiz, 1879); Recent, Indo-West Pacific.
  
• S. maculosa Mortensen, 1928; Recent, North West Pacific.
  
• S. effluens Mortensen, 1927; Recent, Philippines.
  
• S. tiara (Anderson, 1894); Recent, Indian Ocean.
  
• S. lorioli (Koehler, 1927); Recent, Indian Ocean.
  
• S. albidens Clark, 1925; Recent, Indian Ocean.
  
• S. badia Clark, 1925; Recent, Mauritius.
  
• S. brevicollis (de Meijere, 1904); Recent, Indo-West Pacific.
  
• S. fusispina Mortensen, 1928; Recent, Japan.
  
• S. melitensis (Wright, 1855); Miocene, Mediterranean.

Classification and/or Status：

Cidaroida頭帕目, Cidaridae頭帕科, Cidarinae.

Possibly not a monophyletic group. Treated here as a subgenusof Tretocidaris.

Echinometra mathaei 梅氏長海膽 aboral view

Echinometra mathaei 梅氏長海膽 apical system view

Echinometra mathaei 梅氏長海膽 oral view

Echinometra mathaei 梅氏長海膽 aboral view, close-up

Echinometra mathaei 梅氏長海膽 lateral view. the following photo are photo at various ortational degree .

Echinometra mathaei

(Blainville, 1826)

梅氏長海膽      (沒事海膽)

Echinometridae長海膽科

SIZE：39.3x33.3x 22mm

LOCALITY：Penghu Is. , Taiwan

Echinometra mathaei 梅氏長海膽 aboral view

Echinometra mathaei 梅氏長海膽 aboral view, close-up

Echinometra mathaei 梅氏長海膽 oral view

Echinometra mathaei 梅氏長海膽 oral view, close-up

Echinometra mathaei 梅氏長海膽 laeral view

Echinometra mathaei 梅氏長海膽 laeral view, close-up

Echinometra mathaei 梅氏長海膽 laeral view, close-up

Echinometra mathaei 梅氏長海膽 laeral view

Echinometra mathaei 梅氏長海膽 laeral view, close-up

Echinometra mathaei 梅氏長海膽 laeral view, close-up

Echinometra mathaei 梅氏長海膽 laeral view, close-up, cross-sectional view of primary spine

Echinometra mathaei 梅氏長海膽 laeral view, close-up, cross-sectional view of primary spine

Echinometra mathaei 梅氏長海膽 cross-sectional view of primary spine

Echinometra mathaei 梅氏長海膽 cross-sectional view of primary spine

Echinometra mathaei 梅氏長海膽 cross-sectional view of primary spine

Echinometra mathaei 梅氏長海膽 cross-sectional view of primary spine

Echinometra mathaei 梅氏長海膽的生態影片(被攝影者翻身成口面向上)

Prionocidaris glandulosa, teeth, oral  view.

Prionocidaris glandulosa, primary spines.

Prionocidaris glandulosa, primary spines, close-up.

Prionocidaris glandulosa, primary spines, close-up.

Prionocidaris glandulosa, primary spines, close-up.

Prionocidaris glandulosa, pedicellariae, close-up.

Prionocidaris glandulosa, pedicellariae, close-up.

Prionocidaris glandulosa, pedicellariae, close-up.

Prionocidaris glandulosa, pedicellariae, close-up.

Prionocidaris glandulosa, denuded, aboral  view.

Prionocidaris glandulosa, denuded, oral  view.

Prionocidaris glandulosa, denuded, lateral  view.

Prionocidaris glandulosa, denuded, lateral view.

Prionocidaris glandulosa, cleaned, aboral  view.

Prionocidaris glandulosa, cleaned, oral  view.

Prionocidaris glandulosa, cleaned, lateral view.

Prionocidaris glandulosa, cleaned, lateral view, close-up.

Prionocidaris glandulosa, cleaned, lateral view.

Prionocidaris glandulosa, cleaned, lateral view, close-up.

Prionocidaris glandulosa, more cleaned, aboral  view.

Prionocidaris glandulosa, more cleaned, oral  view.

Prionocidaris glandulosa, more cleaned, lateral view.

Prionocidaris glandulosa

(de Meijere 1904)

SIZE：32x 17.5mm

FAMILY：Cidaridae頭帕科

LOCALITY：Penghu Is. Taiwan .

Prionocidaris glandulosa, aboral  view.

Prionocidaris glandulosa, oral  view.

Prionocidaris glandulosa, lateral view.

Prionocidaris glandulosa, aboral  view.

Prionocidaris glandulosa, oral  view.

Prionocidaris glandulosa, Lateral view.

Prionocidaris glandulosa, Lateral view.

Prionocidaris glandulosa, aboral view.

Prionocidaris glandulosa, Oral view.

Prionocidaris glandulosa, Lateral view.

Prionocidaris glandulosa, Lateral view.

Prionocidaris glandulosa, ambulacrum close-up.

Salmacis sphaeroides (Linnaeus, 1758)

雜色角孔海膽

Size：56.6x 33.2mm

Family：Temnopleuridae刻肋海膽科

Locality：Pangandaran Bay, Indonesia.

Salmacis sphaeroides雜色角孔海膽經常可以於貝殼店或海邊觀光禮品店買得到，由於其灰綠色的殼且量多而便宜，吸引人們買來當禮物或紀念品。各位如果到墾丁等觀光區，一定可以看得到，甚至可能是你第一個買到的海膽收藏品。

Stomopneustes variolaris (Lamarck, 1816)

口鰓海膽

Family：Stomopneustidae口鰓海膽科。

Common name：粗刺黑膽。

Size：70mm

Lacality：North East of Taiwan .

Stomopneustes  variolaris 70mm, Lateral view, Ambulacral area↓

Stomopneustes  variolaris 70mm   Lateral view, Detail of
Interambulacrum plating. round zig-zag median sutural line↓

Stomopneustes  variolaris 70mm   Lateral view,
Detail Ambulacral plating,
2 major vertical line of alternative primary tubercle ↓

Stomopneustes  variolaris 70mm, ambital area,
3 serial of pore-pairs↓

Stomopneustes  variolaris 70mm, Aboral view↓

Paracentrotus lividus (Lamarck, 1816)

Size：52.5mm

Family：Parechinidae

Locality：Turkey. Enez. North of Aegean Sea

Test體殼：由反口面及口面俯瞰體殼的輪廓接近圓形，側面呈口面扁平的圓錐體或半球形，殼高約為殼直徑的1/2強，口部平坦但輕微凹陷，口圍約佔殼體直徑的1/3，頂系很小，約只佔殼體的1/6，成體體殼直徑最大約70mm左右。

Apical system(頂系)：紫海膽的頂系為dicyclic disc型，篩板大，所有的oculogenital cycle都有小疣分佈於內側，但ocular plate的小疣則較不顯著，口圍板大但數量不多，有些還有小疣分佈其上。

Ambulacra(步帶區)： 「對孔弧」在殼體口面由5-6個(5個最常見) Pore-pairs組成，在殼體反口面則由3-4個孔對組成，這一「對孔弧」的第一對從2個大疣之間開始向外向下沿著兩小疣斜走至下一個「對孔弧」的上方停止。步帶區的中央有兩排大疣交錯而行，於赤道區的疣最大，而兩排大疣之間也出現一排小疣分佈於Perradial suture兩旁。

Interambulacra(間步帶區)：兩排規則垂直排列的大疣，每排大疣左右又各有2排小疣伴隨而行，形成一橫走的「疣橫列」，上下方還有橫走的furrow分開每個「疣橫列」，疣於ambitus區域最大，而Median suture(中央縫合線)呈不規則圓滑鋸齒狀。

Peristome口圍：約為殼直徑的1/3，口部平坦但輕微凹陷，輪廓約為圓形，但被Buccal notches 把邊緣雕刻成鋸齒狀。

Spine棘刺：棘刺粗而長，成體的棘刺最長不大於殼直徑的一半，但幼體的棘刺相對較長。

Color顏色： 棘刺顏色變異甚大，紫色、棕色、墨綠色都有。但其裸殼大多呈暗綠色，頂系的顏色最深。在囗面步帶溝對孔處顏色則會較淡綠色。殼上有許多大小不一呈輻射排列的外為淡綠色中央為紫綠色凸瘤。體殼上棘刺基部疣突呈紫色。

Biology生物特性：紫海膽多生活於都多浪區，很會挖洞躲藏，常把岩礁岸挖成蜂窩狀。喜愛將一些海草或貝殼放在身上，以防日曬或掠食者的侵襲。在歐洲人們喜愛食用其肥滿的生殖腺。

Distribution分佈：主要分布在整個地中海海域與北從愛爾蘭南至西沙哈拉的大西洋，潮間帶至100公尺深。

參考資料：Sea Urchin  P194