Functional morphology of the reproductive system of Galathea intermedia (Decapoda: Anomura)

Abstract

Spermatophore formation in Galathea intermedia begins in the proximal part of the vas deferens. The contents subsequently form a spermatophoric ribbon, the so-called "secondary spermatophore," in its distal part. A strongly muscular ductus ejaculatorius is present in the coxa of the fifth pereiopod which builds up pressure for the extrusion of the spermatophoric ribbon. After extrusion, the ribbon is caught by the first gonopod, while the second gonopod dissolves the matrix of the ribbon. During copulation the spermatophores are randomly placed on the sternum of the female, near the genital opening, by the fifth pereiopods of the male. Subsequent ovulation of the female via the genital opening, an active process accomplished through muscular activity, results in fertilization of the eggs by the exploding spermatophores. External intersexes are characterized by both male and female external sexual characters, but in all individuals only male gonads are present. No trace of a female reproductive system could be detected. Thus, these external intersexes are exclusively functional males.

Intersexuality in the porcellanid crab Pisidia longicornis (Crustacea: Decapoda: Anomura: Porcellanidae)

“…In Anomura, most studies on intersexuality involve the hermit crab families Coenobitidae and Diogenidae (TURRA 2004, GUSEV & ZABOTIN 2007, FANTUCCI et al 2007, SANT'ANNA et al 2010. Some research has also been conducted on squat lobsters, Galatheidae (KRONENBERGER et al 2004) and mole crabs, Hippidae (SUBRAMONIAM 1981).…”

Absence of a prezygotic behavioural barrier to gene flow between the two sympatric morphs of the squat lobster Munida gregaria (Fabricius, 1793) (Decapoda: Anomura: Galatheidae)

“…1 Helgol Mar Res (2011) 65:513-523 519 gonopores and pleopods (Pohle 1989). Due to the important development and modification into gonopods of the first and second pleopods of Galathea intermedia, Kronenberger et al (2004) suggested that gonopods, as well 5th pereopods, must play some role in spermatophore transfer or related activities. In M. gregaria, the first and second pleopods of males are well developed and modified into gonopods, and spermatophore morphology resembles that of Galathea intermedia.…”

“…Since the knowledge about the reproductive behaviour of galatheids is poor (Kronenberger et al 2004), a first description of the mating behaviour of this species was carried out. We predict that if behavioural reproductive isolation exists between the two forms then: (a) mating encounters between individuals of the same morph (homotypic) will be more frequent than those between different morphs (heterotypic), and that (b) the total time spent in such behaviours will be greater between individuals of the same morph than between individuals of different morphs.…”

[No Title Available]

“…El primer par de pleópodos (gonopodo=G1) es tubular y dirige la corriente de esperma hacia el gonoporo femenino; el (G2) actúa como pistón que impulsa la masa de espermatóforos hacia la espermateca (BAUER, 1986;KRONENBERGER et al, 2004). En algunas familias como Cancridae y Majiidae (BENINGER et al, 1988;SQUIRES, 1990) ambos gonopodos son apéndices largos de diferente robustez según el grupo.…”

“…En el caparazón de algunos Ocypodidae macho y hembra difieren en las crenulaciones suborbitales y en la forma de la base orbital (CRANE, 1975;SHIH et al, 1999). También es característica en los machos de cangrejos la diferenciación de los pleópodos, el primero es tubular y armado y el segundo, en general menor, actúa de pistón impulsando la masa de espermatóforos hacia el interior de la espermateca (MCLAUGHLIN, 1983;BAUER, 1986;KRONENBERGER et al, 2004).…”