Conservation of aspidochirotid holothurians in the littoral waters of Kenya

Aspidochirotid sea cucumbers (Echinodermata: Holothuroidea) are heavily fished in the littoral waters of Kenya, and stocks have plummeted. In order to conserve and manage these natural resources, appropriate conservation and management plans must to be developed. This can only occur if high quality research on different levels is done. This paper discusses five layers of understanding that should be achieved before holothurian conservation in East Africa can be effective

Knowing and understanding the shallow-water holothurian biodiversity of the western Indian Ocean will even the path for conservation

Extensive harvesting of the shallow-water holothurians from the western Indian Ocean (WIO) may, or most possibly will, decimate the standing stocks so fast that conservation innitiatives as we know them today (marine protected areas) might fail in their purpose. In order to develop a rational conservation and management plan for these natural resources, several projects (research council VUB, Fund for Scientific Research Flanders, Flemish Community) were launched. As a first step, these projects aim at mapping and understanding the holothurian biodiversity of the area under study. Holothurian biodiversity was assessed through de novo sampling along the poorly investigated coast of Kenya and along the better known shores of eastern South Africa. Apart from several important range extensions (new records for the Indian Ocean), these efforts also yielded several species new to science and led to the revision of certain ill-defined or ill-studied genera and subgenera. However, as understanding of the biodiversity of a particular taxon only starts with accurate estimates of species richness and composition, comparison of our results with those reported in the vast amount of literature was carried out. The talk will highlight three subjects: (i) ‘how to do good holothurian taxonomy?’, (ii) ‘what are the systematic implications of good taxonomy?’ and (iii) ‘how is our faunistical and zoogeographical knowledge influenced by the novel systematic decisions?’ In conclusion it will be demonstrated that the obtained results even the path for conservation of this highly wanted natural resource

The <i>Ophiocoma</i> species (Ophiurida: Ophiocomidae) of South Africa

This study raises the number of Ophiocoma species recorded in South African from four to eight. All species are briefly discussed in terms of taxonomy, geographic distribution and ecology. In addition, the juvenile of O. brevipes, found on the underside of adult Ophiocoma brevipes specimens, is described in detail. A neotype is designated for O. scolopendrina

Maintaining native levels of shallow-water holothurian biodiversity in the western Indian Ocean (poster)

In East Africa, holothurian populations are currently reaching depletion due to extensive harvesting for the bêche-de-mer industry in the Far East. However, to date, conservation and management of this fauna in an ecosystem approach is currently hardly feasible, for the simple reason that we still fail to name the different players in the game, let alone to monitor the interactions between these or yet other players in the ecosystem.We strongly believe that taxonomic accuracy sets the key to understanding both history and future of holothurian biodiversity, and that only such an approach will result in unambiguous hypotheses of species richness in the different parts of the western Indian Ocean. Our attempts reveal that several flaws in the taxonomy persistently obstructed a clear understanding of holothurian biodiversity. The present study compares the poorly investigated East African situation to the better studied South East African one and stresses that an ecosystem approach is difficult to attain before the taxonomy has reached sufficient stability

Towards an understanding of the shallow-water echinoderm biodiversity of KwaZulu-Natal, Republic of South Africa

Prior to this study, 130 shallow-water (i.e. less then 50 m deep) species of echinoderms were reported from the subtropical (26°S/32°E -30°S/30°E) east coast of South Africa. The Indo-Pacific and the endemic components of this fauna made up 93 % of the species, while the circumtropical, the Atlantic and the cosmopolitan components represented only 7% of the echinoderm fauna. A current study in the KwaZulu- Natal province has added some 39 % of new records (excluding the Crinoidea) to the echinoderm fauna of this province. Changing its endemic component from 26 to 21 %, the Indo-Pacific component from 68 to 73 % with the other components remaining more or less stable. Total echinoderm species distribution of KwaZulu-NataI was analyzed with the second Kulczynski coefficient, a measurement of similarity between two bioassociational areas. This analysis reveals that while the faunistic components of KwaZulu-Natal seem rather homogeneous, the area in the region of St. Lucia Bay appears to be characterized by a high species turn-over

Towards an understanding of the shallow-water holothuroid fauna (Echinodermata: Holothuroidea) of the western Indian Ocean

The study of the Holothuroidea, commonly known as sea cucumbers, started some 23 centuries ago when Aristotle defined them as a kind of motionless marine organisms. Only in the mid sixteenth century were holothuroids recognized as animals per se. Nowadays, Holothuroidea is firmly recognized as one of the five extant classes of echinoderms. Currently some 1600 species are described; these occur from the intertidal to the deep ocean trenches and from the polar to the tropical regions.The ultimate aim of this dissertation is to understand the shallow-water holothuroid biodiversity of the western Indian Ocean, the area stretching from Suez to Cape Town and from the East African coast (Red Sea and Persian Gulf included) to 65 degrees East. To attain this goal, several expeditions to two contrasting regions of the western Indian Ocean (the tropical coast of Kenya together with Pemba Island in northern Tanzania and the subtropical coast of KwaZulu-Natal in the northeast of the Republic of South Africa) were undertaken. The purpose of these was to assemble a representative collection of species.An extensive part of this dissertation is concerned with the construction of a reliable and up-to date faunistical list of the holothuroid fauna of these two case areas. The faunistics of the rest of the western Indian Ocean was tilled in with the aid of important collections from the Seychelles and Inhaca (which were deposited as largely unidentified material in the collection of the Royal Africa Museum, Tervuren, Belgium), with detailed study of virtually all the available literature as well as with numerous loans of specimens from museums worldwide. In the course of the construction of this species inventory, my colleagues and I discovered several species and one genus new to science. We, however, did not blindly follow the standing biological classifications when describing our findings. Au contraire, while constructing the species lists we took great care to critically question the employed classifications. This attitude resulted in the taxonomic revision of the Holothuria subgenus MertensiothuriaLabidodemas. Interestingly, the type species of the latter genus revealed itself as a cryptic species. We were rewarded with the discovery of two additional new species.Throughout this process, the historical opinions towards holothuroid taxonomy and systematics were never denied. This approach enabled us to revive methodically ignored characters such as the ossicles from the musculature. These characters proved not only diagnostic in the recognition of taxa, but also were informative in terms of recovery of phylogenies. By using our rejuvenated insights into such (and other) characters we were able to construct a large, morphology-based dataset, which allowed the recovery of the phylogeny of the Holothuriidae, the family best represented in this work. This cladistic analysis not only revealed that Labidodemas was indeed monophyletic {as suggested by our earlier systematic revision), but also allowed us to state that it has arisen fiom within the (now paraphyletic) genus Holothuria. As such, Labidodemas is evolutionary much younger than generally assumed. Our phylogenetic studies further suggest a close relationship between the genera Actinopyga, Bohadschia and Pearsonothuria, but unfortunately the recovered support proved low. Future studies (see also annex on CD Rom) will have to decide whether a new classification of the Holothuriidae is desired.Taking all these caveats into account, we finally succeeded to construct the wanted faunistical list of the Holothuroidea from the western Indian Ocean. This list was then further used to analyze the patterns of biodiversity by means of cluster analysis on several bèta-diversity coefficients and parsimony analyses of endemicity. These analyses showed that the investigated holothuroid fauna of th

A new species of <i>Bohadschia</i> (Echinodermata, Holothuroidea) from the Western Indian Ocean with a redescription of <i>Bohadschia subrubra</i> (Quoy & Gaimard, 1833)

Bohadschia atra sp. nov. from the Western Indian Ocean is described and compared with Bohadschia subrubra (Quoy & Gaimard, 1833). B. subrubra is redescribed and compared to the new species and related Bohadschia species. The shape of the ossicles varies with body size for both species