PEMBERTON, AJ*; BISHOP, JDD; Marine Biological Association of the UK; Marine Biological Association of the UK and University of Plymouth: Plant-like mating in sessile animals by the release and uptake of aquatic sperm In contrast to copulatory mating or broadcast spawning for external fertilization, a diverse range of marine animals release dispersing aquatic sperm which […]

THOMSON, JD; University of Toronto: Perspectives on the evolution of sexual tactics in animal-pollinated plants: pollen presentation theory and sex allocation theory Many researchers seeking to understand the great range of sexual expression in flowering plants have referred to sex allocation theory for general conceptual insights. Other approaches are possible. With various colleagues, I have […]

LORENZI, M.C.; SELLA, G.; SCHLEICHEROVA, D.; Univ. of Turin, Italy; Univ. of Turin, Italy; Univ. of Turin, Italy: Life history and sex allocation strategies in a simultaneously hermaphroditic polychaete worm The selective advantage of hermaphroditism over gonochorism may reside in the ability of hermaphrodites to adjust relative male and female investment via phenotypic plasticity and/or […]

MILINSKI, M; Max-Planck-Institute of Limnology, Pl�n, Germany: Fitness consequences of selfing and outcrossing in the cestode Schistocephalus solidus S. solidus is a simultaneous hermaphroditic cestode, which passes through two sequential intermediate hosts, i.e. a copepod and the three-spined stickleback fish, until it reproduces in the gut of its definitive host, i.e. any fish-eating bird, which […]

ST. MARY, Colette M; SINGLER, Heather; SABASTIZABEL, Maria N; University of Florida; University of Texas Marine Science Institute; University of Florida: Consequences of variation in sexual selection for sex allocation in simultaneous hermaphrodites: effects of population density Sexual selection typically consists of competition among males for access to mates and female preference for males. In […]

MARTINDALE, M.Q.; FREEMAN, G.; Univ. of Hawaii, Honolulu; Univ. of Texase, Austin: The origin of mesoderm in phoronids. A large number of metazoan phyla (e.g. mollusks, annelids, nemerteans, sipunculids, echiurans) display a highly stereotyped pattern of early development called spiral cleavage. The conservation of the spiralian developmental program allows embryologists to identify homologous cells in […]

M�LLER, MCM*; Universit�t Osnabr�ck, Germany: Polychaete nervous systems: Ground pattern and variation In Annelida as well as in other invertebrate taxa the nervous system is considered to be a most conservative organ system. According to the Articulata-hypothesis the specific structure of the rope-ladder-like nervous system is an autapomorphic character that unifies Annelida and Arthropoda. Immunhistochemical […]

MASLAKOVA, S; MARTINDALE, M; NORENBURG, J; George Washington Univ., Washington DC; University of Hawaii, Honolulu, HI; NMNH, Smithsonian Institution, Washington DC: Hidden trochophore in nemertean development revealed by confocal microscopy and cell lineage analysis Nemerteans belong to the protostome clade the Trochozoa, which includes annelids, mollusks, sipunculids, echiurids and entoprocts. All trochozoan phyla, except nemerteans […]

PAGE, L.R.; University of Victoria, B.C., Canada: Comparative studies of gastropod development: insights into the evolution of a novel body plan A fundamentally important problem in Biology is to understand how new body plans originate during evolution. Insights into this central issue of evolutionary biology will come from studies on the organization of development. We […]

LEYS, SP; University of Alberta: Sponge development: using microscopy to understand key features of the metazoan body plan. Sponges (Porifera) are enigmatic animals whose unusual body plans make interpreting phylogenetic relationships within the group and with other basal metazoan taxa a difficult task. Although molecular approaches have offered new insights, some questions can only be […]