Chemical Mediation of Sperm Activity and Longevity in the Solitary Ascidians Ciona intestinalis and Ascidiella aspersa

1996 ◽  
Vol 190 (3) ◽  
pp. 329-335 ◽  
Author(s):  
T. F. Bolton ◽  
J. N. Havenhand
Keyword(s):  
Ciona Intestinalis ◽  
Chemical Mediation ◽  
Ascidiella Aspersa

scholarly journals The annual growth and reproductive cycle in four ascidians

1952 ◽  
Vol 31 (1) ◽  
pp. 41-61 ◽  
Author(s):  
R. H. Millar
Keyword(s):  
Reproductive Cycle ◽  
Annual Cycle ◽  
Ciona Intestinalis ◽  
Annual Growth ◽  
Botryllus Schlosseri ◽  
Incomplete Knowledge ◽  
Ascidiella Aspersa

This study was undertaken to increase our very incomplete knowledge of the annual cycle inascidians.Berrill (1950) states that ‘the age of ascidians, with one exception, is practically impossible to estimate, unless a certain inhabited area is followed closely through seasons and years’. In the present work the method has been to follow certain aspects of the ascidian population of a chosen area for a period of nearly two years. The area was the Old Dock in Ardrossan Harbour, Ayrshire, and the ascidian population contained four species: Diplosoma listerianum (Milne Edwards), Ciona intestinalis (Linnacus), Ascidiella aspersa (Müller) and Botryllus schlosseri (Pallas). Diplosoma belongs to the order Enterogona, suborder Aplousobranchiata; Ciona and Ascidiella to the order Enterogona, suborder Phlebobranchiata; and Botryllus to the order Pleurogona, suborder Stolidobranchiata. Thus each of the three main suborders is represented, and the four ascidians studied are amongst the commonest British species.

Nitrogen Excretion in Ascidiacea

1957 ◽  
Vol 34 (3) ◽  
pp. 297-305
Author(s):  
IVAN GOODBODY
Keyword(s):  
Metabolic Rate ◽  
Blood Cells ◽  
Ciona Intestinalis ◽  
Nitrogen Excretion ◽  
Soluble Nitrogen ◽  
Filter Feeding ◽  
Protein Nitrogen ◽  
Insoluble Form ◽  
Ascidiella Aspersa

1. Ascidians, have hitherto been regarded eliminating their nitrogen in an insoluble form and storing the products either in special vesicles or in blood cells termed nephrocytes. 2. Three specks of ascidian have been studied: Ciona intestinalis, Ascidiella aspersa and Molgula manhatteniss. Evidence is brought forward to show that these ascidiane excrete soluble nitrogen chiefly in the form of ammonia. 3. The quantities of soluble non-protein nitrogen excreted are slightly higher than is found in the filter-feeding molluscs; this is probably due in part to an increased metabolic rate subsequent to transport and handling. 4. Ammonia may form as much as 95% of the total aon-protein nitrogen excreted. 5. The methods employed are subject to an error up to 10%.

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