Adv. mar. Biol., Vol. 6, 1968, pp. 271--375
SOME ASPECTS OF THE BIOLOGY OF THE
CHAETOGNATHS
ELVEZIO GHIRARDELLI
Istituto d i Zoologia e Anatomia Comnparata della
Universita d i Trieste, Italy
1.
11.
111.
IV.
v.
VI .
VII.
VIII.
Introduction
. .
. .
. .
..
..
. .
General Morphology
. .
. .
..
..
. .
A.
The Eyes, Hooks and Tccth..
..
B.
Integument, Fins and Tail . . . .
..
C.
Corona ciliata . .
..
..
..
. .
Reproduction . .
. .
. .
. .
..
. .
A.
The Male Genital Apparatus
. .
..
B.
The Female Reproductive Apparatus. General
C.
Spermatogenesis and Oogenesis
. .
. .
D.
Fertilization
..
..
..
E.
Laying ofthe Eggs
. .
..
F. Habitat and Cycles of Sexual Maturity . .
Regeneration
. .
. .
. .
..
..
. .
Affinities and Systematic Position
. .
. .
..
Laboratory Experiments
. .
..
. . ..
Acknowledgements
. .
. .
..
..
. .
References
. .
..
..
..
..
..
..
. . . .
. . . .
. .
. .
. .
..
. .
. .
..
. .
..
..
. .
..
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
I .
. .
..
. .
. .
..
..
..
.. 271
, . 271
. . 273
. . 274
. . 281
. . 289
. . 289
. . 292
. . 309
.. 322
. . 335
. . 343
.. 351
. . 355
.. 364
.. 365
. . 366
I. INTRODUCTION
The purpose of this review is to cover certain aspects of the biology
of the chaetognaths, paying particular attention to the biology of
reproduction and to some organs and functions that have not been
previously studied. Therefore, as far as morphology is concerned, only
new information is mentioned and the reader is referred to the monographs quoted in the text for matter that is generally known. Obviously
there may be some repetition or overlapping with other works (for
example that of Alvariso), but in any event the reader will not lack
references in this text to the work of previous authors. My intention
has been to present a survey, as up-to-date as possible, of present
knowledge concerning this interesting group of animals.
11. GENERAL MORPHOLOGY
The morphology of chaetognaths has been described in several
monographs, particularly those by Burfield (1927), John (1933), Kuhl
(1938), Hyman (1959) and de Beauchamp (1960). I n these works, and
271
SOME ASPECTS OF THE BIOLOGY OF THE
CHAETOGNATHS
ELVEZIO GHIRARDELLI
Istituto d i Zoologia e Anatomia Comnparata della
Universita d i Trieste, Italy
1.
11.
111.
IV.
v.
VI .
VII.
VIII.
Introduction
. .
. .
. .
..
..
. .
General Morphology
. .
. .
..
..
. .
A.
The Eyes, Hooks and Tccth..
..
B.
Integument, Fins and Tail . . . .
..
C.
Corona ciliata . .
..
..
..
. .
Reproduction . .
. .
. .
. .
..
. .
A.
The Male Genital Apparatus
. .
..
B.
The Female Reproductive Apparatus. General
C.
Spermatogenesis and Oogenesis
. .
. .
D.
Fertilization
..
..
..
E.
Laying ofthe Eggs
. .
..
F. Habitat and Cycles of Sexual Maturity . .
Regeneration
. .
. .
. .
..
..
. .
Affinities and Systematic Position
. .
. .
..
Laboratory Experiments
. .
..
. . ..
Acknowledgements
. .
. .
..
..
. .
References
. .
..
..
..
..
..
..
. . . .
. . . .
. .
. .
. .
..
. .
. .
..
. .
..
..
. .
..
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
I .
. .
..
. .
. .
..
..
..
.. 271
, . 271
. . 273
. . 274
. . 281
. . 289
. . 289
. . 292
. . 309
.. 322
. . 335
. . 343
.. 351
. . 355
.. 364
.. 365
. . 366
I. INTRODUCTION
The purpose of this review is to cover certain aspects of the biology
of the chaetognaths, paying particular attention to the biology of
reproduction and to some organs and functions that have not been
previously studied. Therefore, as far as morphology is concerned, only
new information is mentioned and the reader is referred to the monographs quoted in the text for matter that is generally known. Obviously
there may be some repetition or overlapping with other works (for
example that of Alvariso), but in any event the reader will not lack
references in this text to the work of previous authors. My intention
has been to present a survey, as up-to-date as possible, of present
knowledge concerning this interesting group of animals.
11. GENERAL MORPHOLOGY
The morphology of chaetognaths has been described in several
monographs, particularly those by Burfield (1927), John (1933), Kuhl
(1938), Hyman (1959) and de Beauchamp (1960). I n these works, and
271