Coastal Tropical Habitats around Douala, Cameroon - January 2020

Описание: In this video a survey in January 2020 studied the coastal freshwater and estuarine systems north and south of Douala - Cameroon.

The first set of watercourses pictured in this video are tributaries of the lower Mungo River which is Cameroon's 6th largest river with a mean annual discharge of 164 m3/s and a catchment area of 4 200 km2 (Stiassny et al. 2007).

Lowland rivers with characteristic deep channels, thick detritus substrates and full canopy cover were found to be the dominant tributary form of the lower Mungo River. Levees created by the sediment regime of the Mungo River have created extensive swampforest floodplains at the confluence of the lowland tributaries and the Mungro River.

Foothill streams flowing through valleys in the lower Mungo River system contain clear strong flowing water with instream and marginal vegetation such as Nymphae sp. Where streams intersect swamp forest braided channels form, which was found to be suitable habitat for Pantodon buchholzi (1:39).

Sampling of the lowland river habitat type found Xenomystus nigri (3:08) and Papyrocranus afer (3: 12). Flooded margins of the lowland rivers were found to contain shallow streams of water with thick layers of mud and overhanging cover. This habitat type was found to support Aphyosemion ahli while the Aphyosemion volcanum was found on the margins of the lowland river systems. Odonata were represented by Agriocnemis and Gynacantha species were observed in the swampforest, while open water in the lowland rivers were inhabited by Oxythemis phoenicosceles.

The second set of videos in this clip are tributaries of the Ndonga River system which flows into the extensive Cameroon estuary (3: 18). Short tributaries typically consisting of source swampforest tributaries enter into mangrove systems controlled by tidal discharge. The shallow streams formed in the low tide were sampled and found to contain typical estuarine fish species such as Citharichthys stampflii (3:45), Yongeichthys thomasi (3:49), Awaous laterstriga (3:52) and Periophthalmus barbarus (3:55).

The tributaries draining into the Ndonga estuary consisted of foothill streams flowing through gallery littoral rainforest, with characteristic woody species such as Lophira alata. Sandy substrates with submerged woody materials were common in this river section. These habitats supported Diastatomma tricolor (4:20), Schilbe brevianalis (4:24), Isichthys henryi (4:27), Phractura cf. brevicauda (4:32) and Polycentropsis abbreviata (4:34).

Braided channels in the swampforest contained a mixture of sandy, muddy substrates with thick layers of detritus. Benitochromis nigrodorsalis (5:10), Parauchenoglanis cf. monkei (5:14) and Malapterurus beninensis (5:17) were all found to occupy this habitat type. Topwater fish observed in this habitat also included Aphyosemion koungueense (5:30), Epiplatys infrafasciatus (5:32) and the common lowland riparian dragonfly Umma longistigma (5:35).

The background sounds were recorded with bio-acoustic hardware in the areas where the videos were recorded. Many monkeys, Tinker Barbets, Wood Peckers and frogs can be heard in the sound.

Several of the other fish species captured are presented at the end of the video. If you would like more information follow the facebook group info below:

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