Comparative ultrastructural studies of the zona radiata of marine fish eggs in three genera in Perciformes

Abstract

The eggs of Mugil cephalus were significantly larger than those of Epinephelus malabaricus, and E. coioides, while those of Sciaenops ocellatus were intermediate between E. coioides and M. cephalus. The distribution density of pores in the egg envelope of S. ocellatus was significantly different from that of E. malabaricus and E. coioides. The micropyle diameters were significantly different in the four species. The ultrastructure of the zona radiata surface, the distribution density of pores and the size of eggs were also useful characters for distinguishing among the four species, but the ultrastructural features of the micropyles were the most important of all for egg identification. 2000 The Fisheries Society of the British Isles

Ultrastructural features of the egg envelope of silver carp, Hypophthalmichthys molitrix (Osteichthyes, Cyprinidae)

“…As a fertilizing spermatozoon gains access to the egg surface only by passing through the micropyle, therefore, we concluded that the diameter of the micropyle canal should be slightly larger than that of the sperm head. The diameter of the micropyle canal was larger than in some fishes such as Epinephalus malabaricus (6.36 lm), Mugil cephalus (3.55 lm) and about the same as that of Epinephalus coiooides (9.06 lm) (Li et al 2000). The type of micropyle is another useful character for identification of fish eggs.…”

“…More recently Li et al (2000) underlined the importance of micropyle ultrastructural features for egg identification in three genera of Perciformes. According to them, the ultrastructure of the zona radiata surface, the distribution density of pores and the size of eggs were useful characters to distinguish the four species of Perciformes, but the ultrastructural features of the micropyle were the most important ones for egg identification.…”

“…Shape, number, size of micropyle and also reinforcement type in the micropyle canal; the diameter, number, and arrangement of the accessory openings; the modes of egg attachment to the substrate and the thickness of the membrane have been used for taxonomic purpose (Riehl 1993, Giulianini et al 1994, Chen et al 1999, Li et al 2000, Bless & Riehl 2002. Some of these characters could be considered as general phylogenetic characters.…”

Ultrastructural studies of the morphological variations of the egg surface and envelopes of the African catfish <em>Clarias gariepinus</em> (Burchell, 1822) before and after fertilisation with a discussion of fertilisation mechanism

“…Such a micropyle was similar to Type III of Riehl and Schulte (1977), inasmuch as no micropyle pit was recorded in C. gariepinus eggs. No micropylar pit was found in Epinephelus malabaricus, E. coioides, Sciaenops ocellatus and Mugil cephalus (Li et al, 2000). The micropylar canal of C. gariepinus eggs apparently decreased in diameter after completion of fertilisation-related ooplasmic changes.…”

Morphology of unfertilized mature and fertilized developing marine pelagic eggs in four types of multiple spawning flounders

“…Phylogenetic relationships at the species, genus, or even subfamily level can also be tested using the characters of egg ultrastructure against phylogenies obtained from morphological characters to determine their congruence (Chen et al 1999). In previous studies, outer surface of the egg envelope and microstructure of the micropyle were the noteworthy features for egg identification and phylogenetic analyses in Serranidae, Sparidae, Apogonidae, and Mugilidae (Riehl 1993;Chen et al 1999Chen et al , 2007Li et al 2000;Gwo 2008). However, eggs collected in different stages of development may tend to demonstrate different configurations in morphology (Gwo 2008).…”