Phylum Echinodermata 棘皮動物門


ClassEchinoidea 海膽綱


Family Brissidae 壺海膽科


Scientific name Metalia spatagus


Chinese name: 心形海壺


Author (Linnaeus 1758)


Size 119x106mm


Description Southern Taiwan Strait.





 


 


Metalia spatagus, TEST, Aboral view(反口面).

Well-developed peripetalous faciole.


 


Metalia spatagus, Peripetalous fasciole (周花帶線)

Paired ambulacra petaloid; posterior pair slightly longer than anterior pair and flexed outwards distally. Petals long, parallel-sided and sunken, with narrow interporal zone.


 


Metalia spatagus, Apical system (頂系)




 


Apical disc ethmolytic, with 4 gonopores.


 


Spines and tubercles within peripetalous fasciole not significantly enlarged.


 


Anterior ambulacrum narrow. Pore-pairs small, simple isopores and undifferentiated.


 


Other ambulacra petaloid; petals narrow and sunken, the anterior pair almost at 180 degrees; petals parallel-sided with little perradial space separating the two columns of pore-pairs.


 


Posterior petals subparallel and can be almost confluent adapically; but diverging adambitally.


 


Metalia spatagus, TEST, Oral view(口面).

Peristome wider than long; kidney-shaped; facing largely downwards.


 


Peristome kidney-shaped with projecting labrum.


 


Sternal plates elongate; episternal plates forming part of plastron. Sternal-episternal suture strongly convex towards anterior.


 


Periproct on posterior truncate face.


 


Labral plate short and wide; not extending beyond ambulacral plate 1.


 


Subanal fasciole present; shield-shaped; with anal branches.





 


Well-developed subanal fasciole and 4 subanal pores on each side.


 


Metalia spatagus, TEST, Lt. lateral view(左側面).



 


Metalia spatagus, Anterior petals (前瓣帶) (Lt side), Posterior petals (後瓣帶) (Rt side) & Peripetalous fasciole (周花帶線).

Peripetalous fasciole narrow; indented behind anterior petals.


 


Posterior face truncate and slightly undercut. Test depressed in profile


 


Sternal-episternal suture strongly convex towards anterior. Periproct on posterior truncate face.


 


Metalia spatagus, TEST, Anterior view(前端).

Metalia spatagus, Anterior ambulacral area (前步帶)





 


Metalia spatagus, TEST, Posterior view(後端).



 


Periproct on posterior truncate face.


 


Periproct large, on short posterior face. Slight subanal heel often developed.





 


Well-developed subanal fasciole and 4 subanal pores on each side..


 


Subanal fasciole present; shield-shaped; with anal branches.




 


4 subanal pores on each side.

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