RESUMEN

Although infrequent among primates, twinning is common among strepsirrhines, a group of primates that includes the lemurs of Madagascar. As with any multifetal pregnancy, complications during gestation or even parturition can arise due to various factors (e.g., amniotic infection, stress). On rare occasions during labour of twins, parturition may be delayed between the two neonates, a phenomenon known as ‘delayed interval delivery’ that has been well-documented among the human medical journals. Based on circumstantial evidence, we report an opportunistic account of a habituated, adult female southern bamboo lemur (Hapalemur meridionalis) from Mandena, southeast Madagascar, first giving birth to an infant in midOctober 2013 (found deceased), and then birthing a live infant sometime between 5-21 days later. Similar to cases reported in human medical literature, the second infant survived and appeared to stay healthy until the conclusion of the study. Our account of asynchronous parturition of twins in a non-human primate is, to our knowledge, the first reported case in the literature.

Asunto(s)

Masculino , Animales , Preñez , Primates/embriología , Índice de Embarazo

RESUMEN

Although infrequent among primates, twinning is common among strepsirrhines, a group of primates that includes the lemurs of Madagascar. As with any multifetal pregnancy, complications during gestation or even parturition can arise due to various factors (e.g., amniotic infection, stress). On rare occasions during labour of twins, parturition may be delayed between the two neonates, a phenomenon known as ‘delayed interval delivery that has been well-documented among the human medical journals. Based on circumstantial evidence, we report an opportunistic account of a habituated, adult female southern bamboo lemur (Hapalemur meridionalis) from Mandena, southeast Madagascar, first giving birth to an infant in midOctober 2013 (found deceased), and then birthing a live infant sometime between 5-21 days later. Similar to cases reported in human medical literature, the second infant survived and appeared to stay healthy until the conclusion of the study. Our account of asynchronous parturition of twins in a non-human primate is, to our knowledge, the first reported case in the literature.(AU)

Asunto(s)

Animales , Masculino , Primates/embriología , Índice de Embarazo , Preñez

RESUMEN

The vomeronasal organ (VNO), also known as the Jacobson's organ, is a bilateral chemosensory organ found at the base of the nasal cavity specialized for the detection of higher-molecular weight (non-volatile) chemostimuli. It has been linked to pheromone detection. The VNO has been well studied in nocturnal lemurs and lorises, but poorly studied in diurnal/cathemeral species despite the large repertoire of olfactory behaviors noted in species such as Lemur catta. Here, the VNO and associated structures were studied microanatomically in one adult female and one adult male L. catta. Traditional and immunohistochemical procedures demonstrate the VNO epithelium consists of multiple rows of sensory neurons. Immunoreactivity to Growth-associated protein 43 (GAP43) indicates the VNO is postnatally neurogenic. In volume, the VNO neuroepithelium scales similarly to palatal length compared to nocturnal strepsirrhines. Numerous taste buds present at the oral opening to the nasopalatine duct, with which the VNO communicates, provide an additional (or alternative) explanation for the flehmen behavior that has been observed in this species. The VNO of L. catta is shown to be microanatomically comparable to that of nocturnal strepsirrhines. Like nocturnal strepsirrhines, the VNO of L. catta may be functional in the reception of high-molecular weight secretions.

Asunto(s)

Lemur/anatomía & histología , Órgano Vomeronasal/anatomía & histología , Animales , Femenino , Proteína GAP-43 , Inmunohistoquímica , Lemur/fisiología , Masculino , Neuronas Receptoras Olfatorias/citología , Papilas Gustativas/anatomía & histología , Órgano Vomeronasal/fisiología

RESUMEN

Several prosimian species begin a leap from a vertical support with their back toward the landing target. To reorient themselves from this dorsally facing, head-first lift-off to a ventrally facing, feet-first landing, the animals combine an initial twist with a partial backward somersault. Cinefilms of a captive colony of ringtailed lemurs (Lemur catta) revealed that during leaps from vertical poles to horizontal supports, the backward somersaulting rotations were often initiated while the animals were airborne. How could these prosimians initiate rotations in the absence of externally applied forces without violating angular momentum conservation? The problem was approached through vector analysis to demonstrate angular momentum (H) changes about the three principal (symmetrical) axes of rotation for a series of critical body positions that were extracted from the filmed sequences. One L. catta specimen was segmented to provide the dimensions and weights necessary for modeling the various body positions. These data were also used to calculate moments of inertia about the three principal axes in order to predict if rotations about these axes were stable or metastable. Lemurs, like any projectile, must conserve the total angular momentum (HT ) established at lift-off. HT , however, is a vector quantity that is the resultant of component vectors about the three principal axes. Thus, H about the individual axes may change as long as HT remains constant. Strategically timed tail movements tilted the body, thereby changing the H value about the head-to-toe (twisting) axis. To conserve HT , also aligned along the twisting axis, angular momentum transferred to the somersaulting axis. Owing to the direction of tail-throw, the initiated rotations were partial backward somersaults that brought the hindlimbs forward for landing. This strategy for initiating specific rotations parallels that practiced by human springboard divers.