In honor of Wilfried Westheide on the occasion of his 75th birthday

Abstract

In November 2012, Wilfried Westheide will celebrate his75th birthday, and this issue of Zoomorphology is dedi-cated to him in recognition of his outstanding contributionsto invertebrate morphology, evolution and phylogeny.During his scientific career, which became visible to thescientific community after publication of his first paper in1965 (Westheide 1965), he has published numerous origi-nal peer-reviewed papers, and ever since his retirement inearly 2003, he has continued this scientific work. In addi-tion to his own research, he has edited, written or partici-pated in many textbooks and review volumes, whichcurrently require most of his working time. Among thesepublications, probably one of the best known examples isthe two-volume work ‘‘Westheide W & Rieger RM:Spezielle Zoologie. Springer Spektrum’’; the first edition ofVolume 1 was published in 1996, and in the meantime,both volumes have seen their second edition in 2006 and2010, respectively. Our knowledge about the functional,evolutionary-theory-based morphology of multicellularanimals grows rapidly, and subsequently, new phylogenetichypotheses are being developed. Now, these are more oftenbased on molecular and even phylogenomic data. Surelyproviding a synthesis of these new results, we are lookingforward to the third and revised edition of this successfultextbook. Since the first publication of the ‘‘SpezielleZoologie,’’ it has become the standard textbook for ourgraduate students in the field of comparative, functionaland evolutionary morphology, and in the meantime, it hasbeen translated to other languages as well. Moreover, from2005 to 2011, Wilfried Westheide was editor in chief of theJournal of Zoological Systematics and EvolutionaryResearch and successfully developed this journal. WilfriedWestheide’s genuine scientific contributions in systematiczoology and morphology have been influenced by hisacademic teacher, Professor Peter Ax, who inspired him tostudy the interstitial fauna of marine sands and thus becamea specialist in interstitial polychaetes (e.g., Westheide1967), and his interest in these tiny and beautiful creaturesnever stopped (Westheide 2008). Here, one focus of hisscientific investigations became the so-called meiofaunaparadox, the seemingly worldwide distribution of manyspecies despite their limited dispersal properties, that is,usually having the capability of producing only a small andvery limited number of eggs and no free-swimming larvae(Westheide 1984). He was among the first to discover thatmany of these so-called cosmopolitan species are in factsibling species to be distinguished by subtle morphologicaland sometimes only by genetic markers; surprisingly, somecosmopolitan species apparently exist (summarized inWestheide 2005). Although published already in 1987(Westheide and Rieger 1987), the contribution on the‘‘amphiatlantic Microphthalmus listensis-species-group’’ isstill an excellent example for this kind of comparativeapproach in morphological phylogenetic work. Besidessuch more basic research, he developed evolutionaryhypotheses on the pathways along which interstitial ani-mals evolved, recognized ‘‘progenesis as a principle inmeiofauna evolution’’ (Westheide 1987), and developednew ideas ‘‘on the direction of evolution within Polycha-eta’’ (Westheide 1997). With the latter contribution basedon functional morphological hypotheses and reasoning, heran into debate with cladistic analyses, which, however,became the leading phylogenetic hypothesis on annelidevolution for more than a decade (Rouse and Fauchald1997; Westheide et al. 1999; Bartolomaeus et al. 2005).Interestingly, molecular studies never established the latter