ANURAN COMMUNITIES AS INDICATORS OF HABITAT TYPES OF A WEST AFRICAN RAINFOREST

ABSTRACT Ecological indicators are that are affected by, and indicate effects of, anthropogenic environmental stress or disturbance on ecosystems. Some anuran species constitute valuable biological indicators of certain types of habitat disruptions. This study aims to evaluate the level of disturbance or conservation of Banco National Park (BNP), a West African rain forest, using anuran assemblage. The standardized transects technique, based on acoustic and visual surveys, was used. We identified 28 species, 13 genera and 8 families in BNP. Typology based on environmental variables and anuran assemblage permit to identify four habitats groups according to disturbance and wetland gradients. IndVal index allowed isolation of 15 indicator species from the 28 species identified. Taxa indicators conserved closed canopy habitats types were, in order of relative importance, Phrynobatrachus liberiensis, P. ghanensis, P. phyllophilus, Morerella cyanophthalma and Aubria subsigillata. Disturbed open habitats were characterized by Ptychadena mascareniensis, P. pumilio, Hyperolius guttulatus, Afrixalus dorsalis, Hoplobatrachus occipitalis, Phrynobatrachus latifrons, Amietophrynus maculatus, Hyperolius fusciventris, Amietophrynus regularis, Hylarana albolabris in order of relative importance. These results showed that BNP was well preserved so far, except for the central clearing and the forest edges which were altered by human activities

THE PUDDLE FROG PHRYNOBATRACHUS LATIFRONS AHL 1924 DIET IN THE FISH FARM OF THE BANCO NATIONAL PARK (IVORY COAST)

ABSTRACT The diet of Phrynobatrachus latifrons, an invasive frog species of the Banco National Park, was carried out in the park fish farm area from March 2004 to February 2005. The prey composition was determined from stomach contents of 60 voucher specimens (30 males and 30 females) with respect to sexes and seasons in order to have a better understanding of the species' ecology. Our results revealed that P. latifrons consumed various prey items ranging from insects, crustaceans, annelids, arachnids, molluscs, millipedes to plant parts. However, at sex level males mainly preferred ants and in addition spiders while ants especially were the major prey of females. With respect to seasons, this anuran preferred mostly preying on winged ants predominantly in the rainy season, and wingless ants and spiders as dominant prey in the dry season. Further surveys should document if the plant parts found in the frog's stomach contents are devoured deliberately or not

UPDATE OF ICHTHYOFAUNA AND ITS CONSERVATION STATUS IN THE AGHIEN LAGOON, CÔTE D’IVOIRE

Istraživanje se usredotočilo na raznolikost ihtiofaune te njen status očuvanja i osjetljivosti u slatkovodnoj laguni Aghien (jugoistočno od Obale Slonovače). Za prikupljanje podataka o ribama korištena su dvapristupa uzorkovanja: eksperimentalni i tradicionalni ribolov. Kao rezultat, 80 vrsta zabilježenih u laguni raspoređeno je u 55 rodova, 27 porodica i 10 redova. Najčešće zastupljeni redovi su Perciformes, Siluriformes, Osteoglossiformes, Characiformes, Cyprusinodontiformes i Pleuronectiformes. Cichlidae, Mormyridae i Clupeidae predstavljale su najraznolikije porodice. Sa pojavnošćuod 100%, najčeste vrste su bile: Brycinus longipinnis, Chrysichthys nigrodigitatus, Pellonula leonensis, Schilbe intermedius i S. mandibularis. U ukupnoj ribljoj populaciji, aprema IUCN crvenoj listi, četiri vrste su opisane kao „skoro ugrožene“ (Coptodon walteri, Marcusenius furcidens, Galeoides decadactylus i Cynoglossus senegalensis), četiri su zabilježene kao „osjetljive“ (B. brevis, Rhexipanchax nimbaensis, Enteromius raimbaulti i Tilapia busumana) i jedna vrsta kao „ugrožena“ (Pseudotolithus senegalensis).Kategorije vrsta koje imaju interes za očuvanje prema IUCN crvenoj listi predstavljaju 10,26% od cjelokupne populacije. Populacija ribe u Aghien laguni podijeljena je u sedam klasa u rasponu od „niske“ do „vrlo visoke“ osjetljivosti, u pogledu osjetljivosti na stres i ribolovni pritisak.This study focused on the diversity of fish fauna, its conservation status and its vulnerability in the Aghien freshwater lagoon (southeast of Côte d\u27Ivoire). For the fish data collection, two sampling approaches were used: experimental fishing and artisanal fishing. As a result, 80 species observed in this lagoon are distributed into 55 genera, 27 families and 10 orders. The best represented orders are the Perciformes, Siluriformes, Osteoglossiformes, Characiformes, Cyprinodontiformes and Pleuronectiformes. The Cichlidae, Mormyridae and Clupeidae represented the best diversified family. With an occurrence of 100%, the most frequent species are: Brycinus longipinnis, Chrysichthys nigrodigitatus, Pellonula leonensis, Schilbe intermedius and S. mandibularis. In the whole fish population, according to IUCN red list, four species where described as Near Threatened (Coptodon walteri, Marcusenius furcidens, Galeoides decadactylus and Cynoglossus senegalensis), four as Vulnerable (B. brevis, Rhexipanchax nimbaensis, Enteromius raimbaulti and Tilapia busumana)and one as Endangered species (Pseudotolithus senegalensis). These categories of species that have a conservation interest according to theIUCN Red List represent respectively 10.26% of the whole population. Fish population of the Aghien Lagoon are divided into seven classes ranging from "low" to "very high" vulnerability, regarding the vulnerability to stress due to fishing pressure

Genetic identification of hybrids between two autochthonous tilapia species,

Tilapia species are able to hybridize in captivity or in natural conditions following introduction of alien species. Here, we report a case of hybridization between two (and perhaps three) autochthonous species, Tilapia zillii and T. guineensis, resulting from a modification of their environment due to human activities. The man-made dam Ayamé (Côte d'Ivoire) transformed the River Bia into a lake (Lake Ayamé, area: 197 km2). In this new environment, both tilapia species have hybridized. In order to study hybridization along the Bia System, 25 allozyme loci have been screened in 470 specimens from ten locations. Two loci LDH-1 and PGI-2 were diagnostic between the two different species and can be used to identify hybrids in each sampling location of the River Bia basin. The percentage of pure T. zillii individuals in Lake Ayamé varied from 18.1% in Ebikro to 4.2% in Kétesso while percentage of pure T. guineensis varied from 81.3% in Yaou to 50.0% in Ebikro. The proportions of hybrids varied from 8.3% in Yaou to 31.9% in Ebikro. The existence of private alleles observed in tilapia from Lake Ayamé compared to what has been observed in both reference populations, T. zillii and T. guineensis led to the hypothesis that a third species could have been engaged in this hybridization. This third species is likely to be T. busumana, formerly present in the lake but now rarely observed. If this natural hybridization is due to the dam construction and the correlated ecological changes, then other hybridizations could result since many dams have been constructed within the range of these species in Côte d'Ivoire

Utilisation des ressources en eaux, assainissement et risques sanitaires dans les quartiers précaires de la commune de Port-Bouët (Abidjan; Côte d’Ivoire)

The sanitation, water sources and utilizations, and the health status of the population about malaria (SPP) and diarrhea (SD) have been evaluated in 6 precarious area (Abattoir, Adjouffou, Derrière wharf, Tofiato, Vridi canal et Zimbabwe) at Port-Bouet in Côte d’Ivoire. An overall of 567 concessions were checked and the population were about 9 741. Human excreta in these areas are dumped in self-sanitation systems (septic tank, unsewered public toilets and family latrines) (8-69%), but 3 to 42% of the inhabitant dumped their excreta in the nature. The clustering of these precarious areas upon sanitation gave 2 groups: Derrière wharf, Adjouffou, Zimbabwe, Tofiato and Vridi canal composed the first group and Abattoir the second one. The discrimination of Abattoir from the others precarious area could be explained by the best sanitation of excreta and rainwater. But, domestic water is dumped on the soil surface (73-100%) in all of the precarious area. Only a few portion of the wastewater is dumped in a septic tank (1-22%). The inhabitants have both access to the potable water distributed by SODECI (99%). This water is essentially used for drinking. The second source of water (well water) in the precarious areas is used as supplement for washing, bathing and as dishwater. The clustering of the precarious area upon water utilization gave 2 groups: Derrière wharf, Tofiato, Adjouffou and Vridi canal composed the first group, and the second one is composed by Abattoir and Zimbabwe. The first group uses more well water than the potable one of SODECI, although in the second group, the potable water is essentially used for all of the duties. The health statues of the inhabitants is worrying, as about 64% are ill, with 45% of SPP and 19% of SD. Children ([0-8 age]) are the most concerned, with 70% of illness, composed of 32% of SPP and of 48% SD

Reproductive biology of Chromidotilapia guntheri (Sauvage, 1882) (Cichlidae, Perciformes) in four coastal rivers (Ehania, Noé, Soumié and Eholié) of Côte d’Ivoire in West Africa

The reproductive activities of a small Cichlid Chromidotilapia guntheri were investigated from July 2003 to March 2005 in four coastal rivers (Ehania, Eholié, Noé and Soumié), in the southeast of Côte d’Ivoire. Trends in gonadosomatic indices and reproductive stages of development suggested that C. guntheri is a multiple (fractional) spawner and breeds all year round with little fluctuation in spawning intensity. However, spawning activities were more intensive in August and September. The estimated mean standard length at first maturity did not differ significantly between rivers. It was, in the overall population, 85.53 mm SL for males and 100.13 mm SL for females. In general, the sex ratio differed from 1:1 with the predominance of the males in rivers, standard length classes, seasons and the entire population. Absolute fecundity (F) varied from a minimum of 70 to a maximum of 470 eggs. The range of variation in the relative fecundity was from 3066 to 9135 eggs per kilogram of fish in the total population. Fecundity did not differ extensively between rivers. The absolute fecundity relations to fish standard length (SL) and eviscerated weight (We) were best described in the whole population by the following equations: F = 0.00069 × SL2.72 and F = 2.54 × We1.15, respectively. Moreover, there was no relationship between absolute fecundity and oocyte diameter

Reproductive biology of

The reproductive activities of a small Cichlid Chromidotilapia guntheri were investigated from July 2003 to March 2005 in four coastal rivers (Ehania, Eholié, Noé and Soumié), in the southeast of Côte d’Ivoire. Trends in gonadosomatic indices and reproductive stages of development suggested that C. guntheri is a multiple (fractional) spawner and breeds all year round with little fluctuation in spawning intensity. However, spawning activities were more intensive in August and September. The estimated mean standard length at first maturity did not differ significantly between rivers. It was, in the overall population, 85.53 mm SL for males and 100.13 mm SL for females. In general, the sex ratio differed from 1:1 with the predominance of the males in rivers, standard length classes, seasons and the entire population. Absolute fecundity (F) varied from a minimum of 70 to a maximum of 470 eggs. The range of variation in the relative fecundity was from 3066 to 9135 eggs per kilogram of fish in the total population. Fecundity did not differ extensively between rivers. The absolute fecundity relations to fish standard length (SL) and eviscerated weight (We) were best described in the whole population by the following equations: F = 0.00069 × SL2.72 and F = 2.54 × We1.15, respectively. Moreover, there was no relationship between absolute fecundity and oocyte diameter

Spatio-temporal patterns of fish assemblages in coastal West African rivers: a self-organizing map approach

We investigated spatio-temporal patterns of fish assemblages in four small coastal rivers in South-East Ivory Coast. The samples were collected between July 2003 and March 2005 at 8 sampling sites (2 per river: 1 upstream and 1 downstream). A total of 59 fish species belonging to 39 genera, 23 families and 11 orders were captured. Perciforms (30% of the families and 33% of the species), followed by Siluriforms (22% and 22%), Osteoglossiforms (13% and 17%), Characiforms (9% and 10%) and Pleuronectiforms (9% and 3%) were the most abundant orders. Among the families sampled, Cichlidae (20% of the species), Mormyridae (13%), Clariidae (10%), Cyprinidae (10%) and Characidae (8%) were largely represented. Among the 59 fish species captured, we identified fifteen marine/brackish species and two introduced species. To analyse patterns of fish assemblages, we used a non-linear clustering technique, the self-organizing map (SOM). Using SOM, samples were classified into 4 clusters, mainly related to the spatial location of the sampling sites. Except for the distance from the source of the river, environmental variables (width, depth, current velocity) did not show a clear distribution gradient on the SOM map. This pattern was explained by the abundance of estuarine/marine species (i.e. 25% of the species) characterizing the lower course of the rivers studied. Such a distribution of estuarine/marine species colonizing the lower and middle course of the rivers was explained by the absence of dams and contrasts with the patterns observed in more fragmented rivers of Ivory Coast. Therefore, we suggest that these small streams should be preserved in order to permit estuarine/marine species to migrate between streams and the Aby lagoon, thus allowing their large distribution and their reproduction in favourable habitats. We suggest particular attention be given to the Soumié River basin which represents the only preserved stream ecosystem within the Bia River basin