Thomas Hincks

Bio: Thomas Hincks is an academic researcher. The author has contributed to research in topics: Hydroid (zoology). The author has an hindex of 1, co-authored 1 publications receiving 84 citations.

Systematics and ecology of the Isefjord marine fauna (Denmark) with a survey of the eelgrass (Zostera) vegetation and its communities

Abstract: This paper represents the results of more than 30 years field observations and research work carried out from the Isefjord Laboratory, Vellerup Vig (Zealand, Denmark), which is owned and financed by the author. The Isefjord complex, 36 km long, including the main fjord and the Roskilde Fjord, and covering about 400 km2, is a shallow (7–10 m, max. 30 m) area dominated by substrata of fine sand to mud with a high content of organic matter. As a guidebook for future research the first part gives information about distribution, systematics, ecology, and breeding of the majority of the 477 animal species described. Nearly 400 species are invertebrates and of the chordates 68 species are true fishes. 63% of all animal species have not previously been recorded from the area, 27 species are new to Danish seas, and one (Polychaeta, Capitellidae) is new to science. The hydrography is treated mainly on the basis of literature. The fjord system may be classified as mixohaline: the Isefjord proper is polyhali...

A Sibling Species Group of Hydractinia in the North-Eastern United States

Abstract: Many symbiotic organisms are narrowly distributed on one or a few host species. These associations are intriguing, as they invite the development of hypotheses regarding the pattern and process of speciation and serve as laboratories for the testing of methods of phylogenetic reconstruction (Kraus, 1978; Futuyma & Slatkin, 1983; Stone & Hawks worth, 1986). The evolution of host-specificity in the sea may be expected to be severely constrained by the difficulty of achieving reproductive isolation in taxa whose gametes are freely released into the water column and/or whose larvae are potentially widely distributed (Scheltema, 1977). Yet this difficulty may well be overestimated, given the recent demonstrations of limited gamete (Pennington, 1985; Yund, in press) and larval dispersal (Knight-Jones & Moyse, 1961; Ryland, 1981; Olsen, 1985; Jackson & Coates, 1986; Grosberg, 1987). Indeed, if gamete and larval dispersal are as limited as has recently been contended (Jackson, 1986), local isolation of populations may be a routine occurence, offering repeated opportunities for speciation.

Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa)

Abstract: Leptothecata are hydrozoans whose hydranths are covered by perisarc and gonophores and whose medusae bear gonads on their radial canals. They develop complex polypoid colonies and exhibit considerable morphological variation among species with respect to growth, defensive structures and mode of development. For instance, several lineages within this order have lost the medusa stage. Depending on the author, traditional taxonomy in hydrozoans may be either polyp- or medusa-oriented. Therefore, the absence of the latter stage in some lineages may lead to very different classification schemes. Molecular data have proved useful in elucidating this taxonomic challenge. We analyzed a super matrix of new and published rRNA gene sequences (16S, 18S and 28S), employing newly proposed methods to measure branch support and improve phylogenetic signal. Our analysis recovered new clades not recognized by traditional taxonomy and corroborated some recently proposed taxa. We offer a thorough taxonomic revision of the Leptothecata, erecting new orders, suborders, infraorders and families. We also discuss the origination and diversification dynamics of the group from a macroevolutionary perspective.

Systematics and Ecology of the Hydroid Population of two Posidonia oceanica Meadows

Abstract: . The ecology and systematics of the hydroid population of Posidonia oceanica meadows have been studied in two different zones of the Western Mediterranean. A new sampling method has been employed and the results obtained have been compared with those of a standard method. The distribution of the species and several morphological variations are pointed out. Depth-related faunistic zones are evidenced. The key-species of the Posidonia hydroid population arc individuated.