Replacement of adult maxillary jaws in Eunicida (Polychaeta)

Replacement of adult maxillary jaws is reported for Diopatra aciculata. The process is similar to arthropod moulting, commencing with apolysis or retraction of the epidermal cells from the inner surface of the old cuticle, followed by formation of the new cuticle. This results in the jaw-in-jaw or p...

Full description

Bibliographic Details
Main Author: Hannelore Paxton
Format: Article
Language:English
Published: Consejo Superior de Investigaciones Científicas 2006-12-01
Series:Scientia Marina
Subjects:
Online Access:http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/138
_version_ 1818719579828912128
author Hannelore Paxton
author_facet Hannelore Paxton
author_sort Hannelore Paxton
collection DOAJ
description Replacement of adult maxillary jaws is reported for Diopatra aciculata. The process is similar to arthropod moulting, commencing with apolysis or retraction of the epidermal cells from the inner surface of the old cuticle, followed by formation of the new cuticle. This results in the jaw-in-jaw or pharate state. Ecdysis or shedding of the old cuticle takes place without any splitting or damage as evidenced by complete, fully articulated shed jaws found in the gut. Newly moulted maxillae are soft and white until they become sclerotized. The new jaws are about 1.4 times the size of the old ones (moult increment). The same process is expected to occur in all extinct and extant Labidognatha. The Recent Lumbrineridae maxillae may not be of the labidognath type, but probably moult in the same manner. Occasional finds of pharate jaws of the extinct Placognatha indicate that they underwent similar jaw replacement. Not enough is known about Prionognatha, although shedding before replacement may occur. Jaw replacement in Ctenognatha, where the new elements form in sac-like epithelial structures ventrolateral to the existing maxillae, is probably limited to this group.
first_indexed 2024-12-17T20:09:12Z
format Article
id doaj.art-cc2b58fccb904ff886232851480cb2af
institution Directory Open Access Journal
issn 0214-8358
1886-8134
language English
last_indexed 2024-12-17T20:09:12Z
publishDate 2006-12-01
publisher Consejo Superior de Investigaciones Científicas
record_format Article
series Scientia Marina
spelling doaj.art-cc2b58fccb904ff886232851480cb2af2022-12-21T21:34:15ZengConsejo Superior de Investigaciones CientíficasScientia Marina0214-83581886-81342006-12-0170S333133610.3989/scimar.2006.70s3331135Replacement of adult maxillary jaws in Eunicida (Polychaeta)Hannelore Paxton0Department of Biological Sciences, Macquarie University, SydneyReplacement of adult maxillary jaws is reported for Diopatra aciculata. The process is similar to arthropod moulting, commencing with apolysis or retraction of the epidermal cells from the inner surface of the old cuticle, followed by formation of the new cuticle. This results in the jaw-in-jaw or pharate state. Ecdysis or shedding of the old cuticle takes place without any splitting or damage as evidenced by complete, fully articulated shed jaws found in the gut. Newly moulted maxillae are soft and white until they become sclerotized. The new jaws are about 1.4 times the size of the old ones (moult increment). The same process is expected to occur in all extinct and extant Labidognatha. The Recent Lumbrineridae maxillae may not be of the labidognath type, but probably moult in the same manner. Occasional finds of pharate jaws of the extinct Placognatha indicate that they underwent similar jaw replacement. Not enough is known about Prionognatha, although shedding before replacement may occur. Jaw replacement in Ctenognatha, where the new elements form in sac-like epithelial structures ventrolateral to the existing maxillae, is probably limited to this group.http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/138jaw moultingjaw sheddingdiopatra aciculataonuphidaeplacognathactenognathaprionognathalabidognatha
spellingShingle Hannelore Paxton
Replacement of adult maxillary jaws in Eunicida (Polychaeta)
Scientia Marina
jaw moulting
jaw shedding
diopatra aciculata
onuphidae
placognatha
ctenognatha
prionognatha
labidognatha
title Replacement of adult maxillary jaws in Eunicida (Polychaeta)
title_full Replacement of adult maxillary jaws in Eunicida (Polychaeta)
title_fullStr Replacement of adult maxillary jaws in Eunicida (Polychaeta)
title_full_unstemmed Replacement of adult maxillary jaws in Eunicida (Polychaeta)
title_short Replacement of adult maxillary jaws in Eunicida (Polychaeta)
title_sort replacement of adult maxillary jaws in eunicida polychaeta
topic jaw moulting
jaw shedding
diopatra aciculata
onuphidae
placognatha
ctenognatha
prionognatha
labidognatha
url http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/138
work_keys_str_mv AT hannelorepaxton replacementofadultmaxillaryjawsineunicidapolychaeta