|Cephalopod eggs and egg masses|
Boletzky, S.V. (1998). Cephalopod eggs and egg masses. Oceanogr. Mar. Biol. Ann. Rev. 36: 341-371
In: Oceanography and Marine Biology: An Annual Review. Aberdeen University Press/Allen & Unwin: London. ISSN 0078-3218, more
|Author|| || Top |
Cephalopod eggs and egg masses turn up in samples taken during oceanographiccruises (including subsamples consisting of the stomach contents of marinepredators); they are encountered by SCUBA divers and crews of mannedsubmersibles, and stranded egg masses can be found on ocean beaches aroundthe world. If it is comparatively easy to identify such material as "squid eggs", it ismuch more difficult to recognize the group or species t which the eggs belong.There are various reasons why the identification of eggs and egg masses is oftendifficult or impossible, especially for the non-specialist. The lack of standardizedillustrated keys showing both the embryonic stages and the corresponding aspectsof egg capsules for well known species is a major impediment to identification orfurther developments needed to optimize the chances of finding hitherto unknownmaterial. To fill the remaining gaps in our basic knowledge of cephalopoddevelopment (e.g. Spirula, Vampyroteuthis), ostensibly rare material may besought in the rich depositories of samples taken during past oceanographic cruises.The chances of finding such material in good condition, with appropriateaccompanying provenance records, increase with any effort made to improvepresent and future sampling strategies and preservation routines. Although it isunderstandable that "gluey stuff" found in plankton nets or dredges brought up byoceanographic vessels in unattractive and therefore tends to be hosed overboard,it should be realized that scientific treasures may thus be lost. This review surveysthe available literature and makes a plea for increased efforts to optimize thechances of finding the rare material by working carefully through the "commonstuff"; the latter then provides other information of great scientific importance. Tomention one aspect that is often overlooked: egg masses may be the only tangibleproof of reproductive activity of a species in a given area, and that proof may beneeded year after year in biological surveys even of common species.