Premium
Embryological aspects of inducible morphological defenses in Daphnia
Author(s) -
Laforsch Christian,
Tollrian Ralph
Publication year - 2004
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.10270
Subject(s) - biology , daphnia pulex , daphnia , predator , embryogenesis , zoology , phenotypic plasticity , brood , embryo , ecology , crustacean , predation , microbiology and biotechnology
Many cases of predator‐induced morphological plasticity in daphnids are well studied examples of inducible defenses. However, little is known about the early development of these sometimes conspicuous traits. We compared for the first time in five different Daphnia species the embryonic development of predator‐induced and noninduced animals using scanning electron microscopy (SEM). We observed significant morphological changes in the last embryonic stage in helmet formation in Daphnia cucullata and in neck‐pedestal development in Daphnia pulex . In contrast, no morphological changes could be found during embryogenesis between induced and noninduced Daphnia lumholtzi, D. longicephala , and D. ambigua . Strategies for initiating the defensive traits differ among Daphnia species because of trade‐offs between environmental requirements and developmental constraints. Some general features of Daphnia embryonic development are described using SEM. All Daphnia embryos have to shed at least three different membranes before leaving the brood pouch of the mother. After the embryos shed the third membrane, chemosensillae that are likely able to detect predator‐released chemicals are exposed to the olfactory environment. J. Morphol. 262: 701–707, 2004. © 2004 Wiley‐Liss, Inc.