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We studied the nesting behavior of the critically endangered West African chimpanzee (Pan troglodytes verus). We assumed that the nesting data stemmed from a single, unhabituated community at the Bagnomba hill site in the savanna-woodlands of southeastern Senegal. The aim of this study was to examine chimpanzees’ nesting habits in terms of the tree species utilized and sleeping nest heights. We recorded a total of 550 chimpanzee nests at Bagnomba between January 2015 and December 2015. The chimpanzees here made nests in particular tree species more often than others. The majority of nests (63%) were in two tree species: Diospyros mespiliformis and Pterocarpus erinaceus. The average height of nesting trees was 10.54 m (SD 3.91, range, 0.0-29.0 m) and average nest height was 7.90 m (SD 3.62, range, 0.0-25.0 m). The result of a linear regression analysis (r = 0.7874; n = 550; p < 0.05) is consistent with a preference for nesting at a particular height. Bagnomba chimpanzees rarely made ground nests (0.36% of nests), but the presence of any ground nesting was unexpected, given that at least one leopard (Panthera pardus) also occupied the hill. This knowledge will enable stakeholders involved in the protection of chimpanzees specifically and of biodiversity in general to better understand chimpanzee ecology and inform a conservation action plan in Senegal where the survival of this species is threatened. [ABSTRACT FROM AUTHOR]

The objective of this work was to identify possible correlations between physicochemical parameters (water temperature, water flow velocity, electrical conductivity, dissolved oxygen, salinity, pH, nitrates, and phosphates) and the spatial distribution in the Senegal River delta of snail species that are intermediate hosts of human schistosomes. Eight water points (ME1 to ME4, NE1 and NE2, TA1 and TA2) were selected in the villages of Menguègne Boye, Ndellé Boye, and Thilla for biweekly monitoring of these snails and the physicochemical parameters of the water. The results show that the spatial distribution of the snail populations is related to pH, dissolved oxygen (mg/l), conductivity, temperature (̊C), and water flow velocity (m/s).

The implementation and expansion of development projects (dams and irrigation schemes) in the Senegal River valley have led to a significant proliferation of snails. We conducted a one-year (2014) study project, monitoring their density in the commune of Richard Toll, to assess the role of environmental parameters on mollusc population dynamics. Four species involved in the transmission of human schistosomiasis were found: Bulinus globosus, B. truncatus, B. senegalensis, and Biomphalaria pfeifferi. Among the intermediate hosts, B. truncatus is the most abundant species, followed by B. globosus. Snail density depends on the nature of the water point but also on environmental parameters such as vegetation. This study showed that vegetation, water level (flood), and flow velocity influence the dynamics of the snail populations that are intermediate hosts of human schistosomes.

Carmyerius marchandi n. sp., a new species of trematode (Paramphistomoidea, Gastrothylacidae), has been described in Senegal. It has an average length of 13 +/- 1 mm and an average diameter of 3 +/- 0.4 mm. The brood pouch, bearing muscular invaginations and a ventrolateral swelling, makes up two thirds of the body length. There is a Carmyerius-type acetabulum. The ratio between the diameter of the acetabulum and body length is 1:7.4. The trematode has a Gastrothylax-type pharynx. The ratio between pharynx length and body length is 1:13.3. The ratio between pharynx length and acetabulum diameter is 1:1.8. The caeca extend beyond the mid section of the parasite. The lobed testicles are in a lateroposterior position. The ovary is situated between the two testicles and the uterus is in a mediodorsal position. The vitelline glands take up a large area in the ventrolateral swelling of the brood pouch. The small genital atrium is of the elongatus type. Using scanning electron microscopy, the parasite's body shows transverse ridging and tegumentary papillae around the oral aperture, genital pore and acetabulum. All of these characteristics indicate that this Gastrothylacidae belongs to the Carmyerius genus. To judge by the other species in the genus previously described, this appears to be a new species. We suggest that it should be named C. marchandi n. sp., as a token of gratitude to Professor Bernard Marchand.

The mature spermatozoa of Cotugnia polyacantha, Raillietina (R) tunetensis, Inermicapsifer madagascariensis and Avitellina centripunctata have an almost identical ultrastructural organization. They are tapered at both extremities. Their anterior extremity exhibits an apical cone of electron dense material and one or two helicoidal crested-like bodies. Their cortical microtubules are spiralized and are seen, in longitudinal and cross sections, as continuous, dense, submembranous material. Their nucleus is a cord of dense chromatin, coiled in a spiral around the 9 + "1" pattern axoneme. The cytoplasm is moderately dense to electron lucent and exhibits irregularly spaced walls of proteinaceous material and a fine periaxonemal sheath of dense material. In this work we show that the Anoplocephalidae are close to the Davaineidae by the characters of the spermatozoon and that Inermicapsifer should be put back among the Davaineidae, according to the opinion of Joyeux & Baer (1961) and come into conflict with other works more particularly Schmidt (1986).

Spermiogenesis in Thysaniezia ovilla begins with the appearance of a differentiation zone equipped with peripheral microtubules, surrounded by arched membranes and containing two parallel centrioles surrounded by electron dense granular material. One of the centrioles aborts, the other gives rise to a flagellum which quickly grows in the cytoplasmic extension in which the nucleus migrates and protein granules form. During the nuclear migration crested-like bodies appear among the peripheral microtubules in the differentiation zone. The Th. ovilla spermatozoon is filiform. One of its extremities, which we show to be anterior, exhibits two helicoidal crested-like bodies, surrounded by electron dense material resembling an acrosome. Cortical microtubules run along almost the whole length of the spermatozoon. The cytoplasm has no mitochondria and contains protein granules. The axoneme is of the 9 + '1' pattern. It stops before reaching the posterior extremity of the gamete. The nucleus is wrapped round the axoneme, in the middle region of the spermatozoon. It generally stops before reaching the posterior extremity of the flagellum. This study has enabled us to describe precisely the orientation of the spermatozoon of cestodes in general.