Abstract
Background. After their deposition in water, eggs of perch form characteristic, long gelatinous ribbons (strands) floating within the water column. The ultrastructure of the external gelatinious egg envelope of members of the family Percidae was believed to be amorphous. The aim of the presently reported study was to describe the ultrastructure and function of the gelatinous egg envelope composing the perch egg ribbon. Materials and methods. Fresh eggs of European perch, Perca fluviatilis L., were collected, in the form of egg ribbons, from females caught at the spawning grounds on the Odra River side canal Dziewoklicz, within the city limits of Szczecin, Poland. After fertilization eggs were fixed in 4%formaldehyde. In the laboratory, the commonly accepted techniques (dehydration, critical-point drying, sputter coating) were used to prepare samples for examination with a scanning electron microscope (SEM). The observations were photographically documented. Results. Closely below the surface of the gelatinous egg ribbon we observed a network of microtubules. These microtubules opened at the egg ribbon surface in the form of ring-like or nozzle-like pores. Conclusion. The gelatinous egg envelope of perch is a complex microtubular network that likely performs a skeletal role for the egg ribbon. Our results also suggest that the regular surface openings of the aforementioned network may play an attachment function (micro-suckers) reciprocally between eggs and between eggs and other objects, thereby facilitating the fastening the eggs to underwater vegetation.
Highlights
The embryonic development of the majority of teleost and the weight of egg cells are determined by their taxofishes takes place in an environment, external to the nomic affiliation
The samples from each female were dehydrated in an alcohol and acetone series, CO2 critical-point dried, mounted on SEM stubs, and sputter coated with gold palladium (Glauert 1981) and observed under a scanning electron microscope (FEI Quanta 200)
Scanning electron microscope examination of the surface of the gelatinous envelope of eggs sampled from the egg ribbon revealed a number of structural surface and envelope-core details which were arranged regularly and showed a repeated pattern
Summary
The embryonic development of the majority of teleost and the weight of egg cells are determined by their taxofishes takes place in an environment, external to the nomic affiliation To facilitate such development a Mikodina 1987, Britz and Bartsch 1998, Britz and number of evolutionary adaptations exist that counteract Cambray 2001, Bless and Riehl 2002, Depêche and adverse environmental effects and favour factors benefi- Billard 1994, Fausto et al 2004, Chen et al 2007, Fava cial to the developing embryo (e.g., factors affecting suit- and Toledo-Piza 2007, Fishelson and Gon 2008, Jiang able spawning time, spawning performance, nest con- et al 2010).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have