Sierra Leone - State of the Marine Environment 2015

5.13. Shoreline and intertidal rocky shore invertebrate species

Modiolus stutorum , Astrangia sp., Oliva accuminata and Rotula orbiculus . The Amphioplus sub-community occurs on mud, shelly- mud and sandy mud in the lower reaches. It is a much more diverse group and may consist of poriferans, brachyurans, crustaceans, gastropods, bivalves, polychaetes and ophuiroids. The representative members may include: Upogebia furcata , Callianassa balssi , Clymene monilis , Pectinoria sourei , Goniada multidentata , Glycera convolute , Deopatia neapolitanea , Nereis senegalensis , Notomastus

Shrimps and crabs of estuaries and deltas are also included here. Only 3 ( Penaeus notialis , Penaeus atlantica and Penaeus kerathurus ) out of 6 species of shrimps are found in the coastal waters of Sierra Leone. There may be post larval stages and juveniles found in plankton. The species of crabs of commercial importance found in the Sierra Leone River estuary are the entire genus Callinectes and are Callinectes pallidus , C. amnicola and C. maginatus . Two of the six shrimp species of commercial importance Penaeus notialis and Penaeus kerathurtus inhabit the mangrove swamps, estuaries and inner continental shelf to a depth of 55m. As in the case above, these fisheries are in good condition. 5.14. Benthic filter feeders of soft and hard substrata Several benthic fauna species occur in the estuaries of Sierra Leone (Tab. 5.1). Longhurst (1958) has identified the following assemblages of benthic organisms in the Sierra Leone River Estuary: Venus community, Amphioplus sub-community, Venus/ Amphioplus transition, P achymelania sub-community and Estuarine gravel community. The Venus community is found near the mouth of the estuary and in the deep channel on shelly-sand and fine lateritic gravel. It is dominated by poriferans, nemerteans, small crustaceans, brachyuran, pagurids, procellanids, lamellibranches, asteroids, echinoderms and ascidians. The most important members include: Brachiostoma leonense , Aloidis sulcate , Astroecten michaelseni , Tris carbonorea ,

Table 5.1: Dominant benthic fauna of Sierra Leone’s estuaries

Polychaeta Clymene monilis Glycera convoluta Diopatra neapolitana Pectinaria souriei Gephyrea (Sipunculidae) Ochetostoma Mercator Branchiopoda Lingula parva Echinodermata Rotula orbiculus Holothuroidea Amphioplus congensis Mollusca Iphigenia truncata Tellina nymphalis Donax owenii Mactra sp. Glycimeris sp. Aloidis dauzenbergi Cephalochordata Branchiostoma leonense Crustacea Squilla africana Callianassa balssi Alpheus pontederiae Penaeus notialis Parapenaeus atlantica Bigelowina septemspinosa

Lumbrineris impatiens Goniada multidentata Terebellida

Sipunculus titubens

Acrocnida semisquamata Ophiuroidea Astropecten michaelseni

Surcula coerulea Pachymelania aurita Neritina oweniana Neritina rubricata Neeritina glabrata Aloidis trigona

Polyonyx sp. Diogenes pugilator Paguristes sp. Uca tangeri Heteropanope caparti Menippe nodifrons Porcellana longicornis Clibanarius cooki

Upogebia furcata Latreutes parvulus

27