Penis Lobes Research Articles

Cuna insularis n. gen. and n. sp. (Isopoda: Cymothoidae) from the Gill Chamber of the Sergeant Major, Abudefduf saxatilis (Linnaeus), (Osteichthyes) in the West Indies

The genus is characterized by having appendix masculina on the first 3 pairs of pleopods of the male, a reduced number of articles in the antennae, basal articles of antennae 1 expanded but not contiguous, antennae 1 expanded, antennae 2 compressed, head immersed in pereonite 1, pleon not immersed in pereon, as wide as pereon, and hunched and compressed. The new species possesses rudimentary penis lobes in the female. Development from a male to a female may be inhibited by the presence of a female. Transition from male to female requires more than one molt in Cuna insularis. Both single and multiple molt sex reversal patterns occur among cymothoids. Erosion exposing the heart of the host was frequently caused by this parasite. Infections of Abudefdufsaxatilis with Anilocra abudefdufi may favor infection with Cuna insularis. This parasite probably has a continental distribution along the Caribbean shores and near shore islands of Central America and northern South America. Cuna insularis is the only species of cymothoid isopod known to possess appendix masculina on the first 3 pairs of pleopods. The appendages and mouthparts of C. insularis are unusually free of hair and setae. While observing, photographing and collecting specimens of the cymothoid, Anilocra abudefdufi Williams and Williams, 1981, occurring exter- nally on Abudefduf saxatilis (Linnaeus) in the San Blas Islands off the Caribbean coast of Pan- ama, we discovered a second isopod in the gill chamber of this fish. Closer inspection showed that, although cymothoid, it did not belong to any of the known genera of Cymothoidae. Metze- laar (1919) identified an isopod taken from the gills of A. saxatilis collected in Cura9ao as Cy- mothoa excisa. We examined his specimen and found it to be identical to our new isopod. We also identified 3 more specimens of this species in a U.S. National Museum collection of fish-

The functional morphology of the reproductive organs of the Common earwing (Forficula auricularia) and other Dermaptera with reference to the natural classification of the order

The functional morphology of the male and female organs of reproduction of the Common earwig (Forficula auricularia L.) are described together with typical examples of the external male genitalia of most sub‐families of the order. Evolutionary trends involve a gradual reduction in the number of penis lobes from two to one; a process which seems to have taken place several times within the Dermaptera. A natural classification of the Dermaptera is suggested in the light of these data.

On the Development of the Male Genitalia and the Efferent Genital Ducts in Lepidoptera

ABSTRACT A general account of the internal reproductive organs and the external genitalia and their development is given. The ‘penis lobes’ develop earlier than the ‘valvae lobes ‘, and independently of them. The tegumen is the modified ninth tergite. The tenth segment is visibly distinguished into a tergal and sternal part in the pupal stages, and the anal tube passes between the two sclerites. The uncus and the gnathos are dorsal and ventral processes respectively of the tenth segment. The anellus lobes develop as lateral processes of the ninth sternite on either side of the penis. The vasa deferentia during larval life do not extend beyond the eighth abdominal segment and lie in a latero-ventral position. They meet the extensions from the ectodermal ‘ductus ejaculatorius duplex’ during the last larval stadium. From the earliest caterpillar stage there exists a pair of ectodermal ducts formed by the differentiation of the epidermis on the ninth sternite. Towards the end of larval life they divide by constriction to form the accessory glands and the ‘ductus ejaculatory duplex’. At this stage they extend on either side to meet the vasa deferentia. The vesiculae seminales develop by distension from the region of junction between the vasa deferentia and the proximal portion of the ejaculatory duct. The ‘ductus ejaculatorius simplex’ arises as an ectodermal invagination between the pair of ‘penis lobes ‘during the final larval instar. It is established that, with the exception of the vasa deferentia, all the remaining elements in the efferent genital system are derived from the ectoderm.