scholarly journals Egg Capsule Catechol Oxidase from the Little SkateRaja erinaceaMitchill, 1825

1988 ◽  
Vol 175 (2) ◽  
pp. 202-211 ◽  
Author(s):  
THOMAS J. KOOB ◽  
DAVID L. COX
Keyword(s):  

Author(s):  
Thomas J. Koob ◽  
David L. Cox

Tanning of the Raja erinacea egg capsule occurs after secretion of capsule precursors from the nidamental gland and involves the introduction of catechols and their subsequent oxidation to quinones by catechol oxidase. At the time of secretion and assembly of capsular precursors in the nidamental gland, the capsule is white, contains no catechols and lacks chemical and mechanical stability. Following formation in the nidamental gland, catechols accumulate in utero in parallel with colour development. An inactive form of catechol oxidase is incorporated in the capsular matrix at the time of secretion. Catechol oxidase activity increases concomitantly with increasing catechol content and colour development.





Zootaxa ◽  
2020 ◽  
Vol 4732 (1) ◽  
pp. 196-200
Author(s):  
CHANG-MOON JANG ◽  
YANG˗SEOP BAE

Parapachymorpha is one of eight genera within the tribe Medaurini of subfamily Clitumninae (Phasmatidae). It was established by Brunner von Wattenwyl (1893), with the type species Parapachymorpha nigra by subsequent designation of Kirby (1904), from Myanmar. Species of this genus are widely distributed in oriental tropics (Laos, China, Thailand, Myanmar, Vietnam and Cambodia), with only 11 known species in the world (Brock et al. 2018, Ho 2017). Species of the genus Parapachymorpha can be recognized by following characters (Brunner von Wattenwyl 1893;1907, Henmemann & Conle 2008, Ho 2017): 1) body robust in female and slender in male with long leg in relation to the length; 2) body surface of female granulose or spinose; 3) mesonotum of female more and less expanded posteriorly; 4) abdominal tergites lacking expanded prostero–lateral angles in both sexes; 5) laminal supraanalis undeveloped in female; 6) semi–tergite of male irregularly rectangular, with an additional finger­–like ventro–apical appendix on the lower margin and reduced or absent; 7) egg capsule oval to oblong and covered with a raised net–like structure in lateral view; 8) micropylar plate oval; 9) operculum concave or convex. In the present study, we describe additional species, Parapachymorpha minuta sp. nov. from Laos, with photographs of both sexes of adults and egg. 



Author(s):  
Abd El-Motaleb M. Ramadan ◽  
Shaban Y. Shaban ◽  
Mohamed M. Ibrahim ◽  
Shehab A. Sallam ◽  
Fawzya I. El-Shami ◽  
...  


1972 ◽  
Vol 11 (8) ◽  
pp. 2415-2421 ◽  
Author(s):  
H.R. Lerner ◽  
A.M. Mayer ◽  
E. Harel


1999 ◽  
Vol 9 (6) ◽  
pp. 677-683 ◽  
Author(s):  
Christoph Eicken ◽  
Bernt Krebs ◽  
James C Sacchettini


Parasitology ◽  
1964 ◽  
Vol 54 (2) ◽  
pp. 295-312 ◽  
Author(s):  
Elon E. Byrd ◽  
William P. Maples

The naturally oviposited egg of Dasymetra conferta is fully embryonated and it hatches only after it is ingested by the snail host, Physa spp.Hatching appears to be in response to some stimulus supplied by the living snail. The stimulus causes the larva to exercise a characteristic series of body movements and to liberate a granular sustance (hatching enzyme) from the larger pair of its cephalic glands. This enzyme reacts with the vitelline fluid to create pressure within the egg capsule, and with the cementum of the operculum, so that it may be lifted away. The larva's escape from the shell, therefore, is due to a combination of pressure and body movements.The hatched larva has a membranous body wall, supporting six epidermal plates, an apical papilla, two penetration glands and a central matrix (the presumptive brood mass).It lives for about an hour within the snail and during this time there is a reorganization of the central matrix which terminates in the formation of an 8-nucleated syncytial brood mass.The miracidial ‘case’, consisting of the body wall and the epidermal plates, ultimately ruptures to liberate the brood mass. Once the brood mass is free it penetrates through the gut wall in an incredibly short time.



2018 ◽  
Vol 85 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Guilherme N Corte ◽  
Leonardo Q Yokoyama ◽  
Márcia R Denadai ◽  
Eduardo Bessa ◽  
Maria Claudia Z Salles ◽  
...  


2011 ◽  
Vol 39 (1) ◽  
pp. 76-83
Author(s):  
Robert B. Suter ◽  
Patricia R. Miller ◽  
Gail E. Stratton
Keyword(s):  


1979 ◽  
Vol 44 (3) ◽  
pp. 261-263 ◽  
Author(s):  
I. SHOMER ◽  
N. BEN-SHALOM ◽  
E. HAREL ◽  
A. M. MAYER


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