This is similar to the gonopodium
of freshwater poeciliids, which also have a modified anal fin ray with specialized muscles that allow the gonopodium
to rotate during copulation (Rosen and Gordon 1953).
(1999) Wa = abdomen width; Lplc = propodus length of the largest cheliped; Lg = length of gonopodium
In males the anal fin is modified to form a structure that is used to fertilize females (gonopodium
Maturation stages (juvenile and adult) were distinguished by the size at which differential growth of the secondary sexual characters (males = gonopodium
length; females = abdomen width) in relation to the independent variable (CW).
The researchers examined the role of a pair of claws at the tip of the gonopodium
of the male guppy (Poecilia reticulata) - essentially the fish's penis.
Most of the fin structure in the male fish is modified into bone, comprising the gonopodium
. This study represents an ultra-structural characterization of the internal morphology of the mosquitofish anal fin.
Phalloceros harpagos is a viviparous species and present marked sexual dimorphism in size, with larger and more robust females (ENDLER, 1983), and morphology, with the presence of a gonopodium
in males (LUCINDA, 2008), and beyond the continuous spawning, presents high fecundity, small size at first maturity and high metabolism, as intrinsic characteristics of the species.
Thrusting was defined as attempts to introduce the male's gonopodium
into the female's genital opening.
Mature male sailfin mollies have a modified anal fin called a gonopodium
, which they insert into the gonopore of a female during a mating attempt.
gracilis, being the modification of the anal fin in males to form a gonopodium
the main sexual distinctive characteristic.
The long-finned fish have problems with mating; the males have difficulty inserting the gonopodium
and transferring spermatophores.
The criterion of hook development on the gonopodium
(Angus et al.