Hatching of an estuarine crab, Sesarma haematocheir: From disappearance of the inner (E3) layer to rupture of the egg case

Masayuki Saigusa, Michihiro Terajima

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Hatching of decapod crustaceans is characterized by the sudden rupture of the egg case. This study focused on the following two issues regarding the hatching mechanism of the estuarine terrestrial crab Sesarma haematocheir: (1) dissolution of the egg case, and (2) the site where the egg case breaks. The egg case comprises three layers: the outer two (E1 and E2) layers and the inner (E3) thin layer (0.2 μm in thickness). The outer layers showed no morphological changes upon hatching, but the inner layer (E3) was markedly digested. The digestion of this layer would enable the embryo to absorb ambient water via reverse peristalsis of the intestine, resulting in an increase of the volume. The egg case always ruptured perpendicular to the longitudinal axis of the embryo. In addition, breakage of the egg case occurred at the dorsal thorax of the embryo. The three major organs positioned at this area were (1) a sharp projection (dorsal spine), (2) an assemblage of muscles, and (3) a pair of secretory glands, each of which was about 30 μm in diameter. The dorsal projection is soft before hatching, and it is clear that the egg case does not break with the posterior expansion of this projection. The rupture instead appears to be caused by the expansion of the muscles arranged perpendicular to the body axis. In addition, some (unknown) factor might weaken the egg case just before hatching. The secretory glands may be a kind of rosette gland, but the role that this gland plays at hatching is not known. As a duct comes out from the center and enters the dorsal projection, some active substance may be released at the tip of this projection. However, immunochemical studies are not consistent with this substance being an ovigerous hair stripping substance (OHSS). (C) 2000 Wiley-Liss, Inc.

Original languageEnglish
Pages (from-to)510-523
Number of pages14
JournalJournal of Experimental Zoology
Volume287
Issue number7
DOIs
Publication statusPublished - Dec 1 2000

Fingerprint

egg masses
crabs
hatching
embryo (animal)
peristalsis
muscles
thorax
Decapoda
hairs
intestines
Crustacea
digestion
water

ASJC Scopus subject areas

  • Animal Science and Zoology

Cite this

Hatching of an estuarine crab, Sesarma haematocheir : From disappearance of the inner (E3) layer to rupture of the egg case. / Saigusa, Masayuki; Terajima, Michihiro.

In: Journal of Experimental Zoology, Vol. 287, No. 7, 01.12.2000, p. 510-523.

Research output: Contribution to journalArticle

@article{04014c213d7b4d8daec10e56471d25aa,
title = "Hatching of an estuarine crab, Sesarma haematocheir: From disappearance of the inner (E3) layer to rupture of the egg case",
abstract = "Hatching of decapod crustaceans is characterized by the sudden rupture of the egg case. This study focused on the following two issues regarding the hatching mechanism of the estuarine terrestrial crab Sesarma haematocheir: (1) dissolution of the egg case, and (2) the site where the egg case breaks. The egg case comprises three layers: the outer two (E1 and E2) layers and the inner (E3) thin layer (0.2 μm in thickness). The outer layers showed no morphological changes upon hatching, but the inner layer (E3) was markedly digested. The digestion of this layer would enable the embryo to absorb ambient water via reverse peristalsis of the intestine, resulting in an increase of the volume. The egg case always ruptured perpendicular to the longitudinal axis of the embryo. In addition, breakage of the egg case occurred at the dorsal thorax of the embryo. The three major organs positioned at this area were (1) a sharp projection (dorsal spine), (2) an assemblage of muscles, and (3) a pair of secretory glands, each of which was about 30 μm in diameter. The dorsal projection is soft before hatching, and it is clear that the egg case does not break with the posterior expansion of this projection. The rupture instead appears to be caused by the expansion of the muscles arranged perpendicular to the body axis. In addition, some (unknown) factor might weaken the egg case just before hatching. The secretory glands may be a kind of rosette gland, but the role that this gland plays at hatching is not known. As a duct comes out from the center and enters the dorsal projection, some active substance may be released at the tip of this projection. However, immunochemical studies are not consistent with this substance being an ovigerous hair stripping substance (OHSS). (C) 2000 Wiley-Liss, Inc.",
author = "Masayuki Saigusa and Michihiro Terajima",
year = "2000",
month = "12",
day = "1",
doi = "10.1002/1097-010X(20001201)287:7<510::AID-JEZ7>3.0.CO;2-G",
language = "English",
volume = "287",
pages = "510--523",
journal = "Journal of Experimental Zoology Part A: Comparative Experimental Biology",
issn = "0022-104X",
publisher = "John Wiley and Sons Inc.",
number = "7",

}

TY - JOUR

T1 - Hatching of an estuarine crab, Sesarma haematocheir

T2 - From disappearance of the inner (E3) layer to rupture of the egg case

AU - Saigusa, Masayuki

AU - Terajima, Michihiro

PY - 2000/12/1

Y1 - 2000/12/1

N2 - Hatching of decapod crustaceans is characterized by the sudden rupture of the egg case. This study focused on the following two issues regarding the hatching mechanism of the estuarine terrestrial crab Sesarma haematocheir: (1) dissolution of the egg case, and (2) the site where the egg case breaks. The egg case comprises three layers: the outer two (E1 and E2) layers and the inner (E3) thin layer (0.2 μm in thickness). The outer layers showed no morphological changes upon hatching, but the inner layer (E3) was markedly digested. The digestion of this layer would enable the embryo to absorb ambient water via reverse peristalsis of the intestine, resulting in an increase of the volume. The egg case always ruptured perpendicular to the longitudinal axis of the embryo. In addition, breakage of the egg case occurred at the dorsal thorax of the embryo. The three major organs positioned at this area were (1) a sharp projection (dorsal spine), (2) an assemblage of muscles, and (3) a pair of secretory glands, each of which was about 30 μm in diameter. The dorsal projection is soft before hatching, and it is clear that the egg case does not break with the posterior expansion of this projection. The rupture instead appears to be caused by the expansion of the muscles arranged perpendicular to the body axis. In addition, some (unknown) factor might weaken the egg case just before hatching. The secretory glands may be a kind of rosette gland, but the role that this gland plays at hatching is not known. As a duct comes out from the center and enters the dorsal projection, some active substance may be released at the tip of this projection. However, immunochemical studies are not consistent with this substance being an ovigerous hair stripping substance (OHSS). (C) 2000 Wiley-Liss, Inc.

AB - Hatching of decapod crustaceans is characterized by the sudden rupture of the egg case. This study focused on the following two issues regarding the hatching mechanism of the estuarine terrestrial crab Sesarma haematocheir: (1) dissolution of the egg case, and (2) the site where the egg case breaks. The egg case comprises three layers: the outer two (E1 and E2) layers and the inner (E3) thin layer (0.2 μm in thickness). The outer layers showed no morphological changes upon hatching, but the inner layer (E3) was markedly digested. The digestion of this layer would enable the embryo to absorb ambient water via reverse peristalsis of the intestine, resulting in an increase of the volume. The egg case always ruptured perpendicular to the longitudinal axis of the embryo. In addition, breakage of the egg case occurred at the dorsal thorax of the embryo. The three major organs positioned at this area were (1) a sharp projection (dorsal spine), (2) an assemblage of muscles, and (3) a pair of secretory glands, each of which was about 30 μm in diameter. The dorsal projection is soft before hatching, and it is clear that the egg case does not break with the posterior expansion of this projection. The rupture instead appears to be caused by the expansion of the muscles arranged perpendicular to the body axis. In addition, some (unknown) factor might weaken the egg case just before hatching. The secretory glands may be a kind of rosette gland, but the role that this gland plays at hatching is not known. As a duct comes out from the center and enters the dorsal projection, some active substance may be released at the tip of this projection. However, immunochemical studies are not consistent with this substance being an ovigerous hair stripping substance (OHSS). (C) 2000 Wiley-Liss, Inc.

UR - http://www.scopus.com/inward/record.url?scp=0034566029&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034566029&partnerID=8YFLogxK

U2 - 10.1002/1097-010X(20001201)287:7<510::AID-JEZ7>3.0.CO;2-G

DO - 10.1002/1097-010X(20001201)287:7<510::AID-JEZ7>3.0.CO;2-G

M3 - Article

C2 - 11110165

AN - SCOPUS:0034566029

VL - 287

SP - 510

EP - 523

JO - Journal of Experimental Zoology Part A: Comparative Experimental Biology

JF - Journal of Experimental Zoology Part A: Comparative Experimental Biology

SN - 0022-104X

IS - 7

ER -