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Coelomogenesis And Nutrition Of Clonally Produced Asteroid Larvae, William Jaeckle
Coelomogenesis And Nutrition Of Clonally Produced Asteroid Larvae, William Jaeckle
William Jaeckle
Asexual reproduction by planktotrophic larvae of asteroids is an unusual life history strategy exhibited by several species in the families Luididae, Oreasteridae, Ophidiasteridae, and Asteriidae. Larvae of the former three families reproduce asexually in the field, while the asteriid Pisaster ochraceus has produced clones when larvae are reared in the laboratory. Our knowledge of the processes involved in larval cloning and the biology of the developing clone is fragmentary in nature. We used light, electron, and scanning laser confocal microscopy to study clones that develop through paratomy of the posterolateral larval arms. The archenteron forms by a modified form of …
Variation In Alanine Transport Among Sibling Lecithotrophic Larvae Of Holothuroid And Asteroid Echinoderms, William Jaeckle
Variation In Alanine Transport Among Sibling Lecithotrophic Larvae Of Holothuroid And Asteroid Echinoderms, William Jaeckle
William Jaeckle
Variation in development rate (e.g., time to metamorphic competence) among sibling larvae has been reported, but inter-individual differences in physiological processes has received comparatively little attention.
Transport And Metabolism Of Alanine And Palmitic Acid By Field-Collected Larvae Of Tedania Ignis (Porifera, Demospongiae): Estimated Consequences Of Limited Label Translocation, William Jaeckle
William Jaeckle
The epidermis of larvae of Tedania ignis(Porifera, Demospongiae) is uniformly ciliated except for the posterior pole. The epidermal cells are long, columnar, and monociliate; each cilium arises from an epidermal crypt; symbiotic bacteria were not observed in larval cells. These lecithotrophic ("nonfeeding") larvae can feed by assimilating dissolved organic materials (DOM) from seawater. Larvae transported both the amino acid alanine (mean = 2.73 pmol larva-1 h-1; [S] = 1 µM) and the fatty acid palmitic acid (mean = 16.27 pmol larva-1 h-1; [S] = 1 µM) from seawater. Following assimilation, the label from alanine was recovered primarily in small molecular …
Multiple Modes Of Asexual Reproduction By Tropical And Subtropical Sea Star Larvae: An Unusual Adaptation For Genet Dispersal And Survival, William Jaeckle
Multiple Modes Of Asexual Reproduction By Tropical And Subtropical Sea Star Larvae: An Unusual Adaptation For Genet Dispersal And Survival, William Jaeckle
William Jaeckle
Sea star larvae (Echinodermata: Asteroidea), collected from the subtropical Northwest Atlantic Ocean, exhibited three distinct modes of asexual reproduction. A number of different bipinnariae and brachiolariae reproduced by paratomous cloning of the posterolateral arms. This morphogenesis was identical to that of larvae assignable to the genus Luidia. A second mode of asexual reproduction involves the autotomization of an anterior portion of the preoral lobe. Primary larvae with preoral lobes of varying sizes and free-swimming preoral lobes of various stages of morphological development were simultaneously collected. The free-swimming preoral lobes developed complete digestive systems and ultimately assumed the form of typical …
Rates Of Energy Consumption And Acquisition By Lecithotrophic Larvae Of Bugula Neritina (Bryozoa: Cheilostomata), William Jaeckle
Rates Of Energy Consumption And Acquisition By Lecithotrophic Larvae Of Bugula Neritina (Bryozoa: Cheilostomata), William Jaeckle
William Jaeckle
Lecithotrophic larvae of the cheilostome bryozoan, Bugula neritina (L.), lose metamorphic competence 12 to 24 h after release from the maternal zooid. The high respiration rate of newly released larvae (mean=306.3 pmol O2 larva-1 h-1, range= 149.3 to 466.6, n=18 trials, 22.5 °C) from adults collected at Link Port, Fort Pierce, Florida during the winter/spring of 1990-1991 reflects their active swimming behavior. The average energy con¬tent per larva was 15.24 mJ (range: 13.35 to 20.17 mJ ind-1, n=5 groups). If all cells have an identical energy content and metabolic rate, then 2 and 20% of the total en¬ergy content would …
Experimental Manipulations Of The Organic Chemistry Of Seawater: Implications For Studies Of Energy Budgets In Marine Invertebrate Larvae, William Jaeckle
Experimental Manipulations Of The Organic Chemistry Of Seawater: Implications For Studies Of Energy Budgets In Marine Invertebrate Larvae, William Jaeckle
William Jaeckle
Correct measurement of changes in biomass and metabolic rates over time are two essential elements for the accurate construction of energy budgets for invertebrate larvae. Both components of larval energetics are altered by changes in the organic chemistry of the seawater. Axenic (bacteria-free) veliger larvae (88 µm shell length) of the bivalve Crassostrea gigas (Thunberg, 1795) had a 53% enhancement of their metabolic rate relative to control values (5.8 ± 0.6 pmol larva -1 h -1 , x¯ ± 1 SE) when exposed to seawater to which 1 µM glucose had been added. Gastrulae increased their rate of respiration by …
Ontogenic Changes In The Rates Of Amino Acid Transport From Seawater By Marine Invertebrate Larvae (Echinodermata, Echiura, Mollusca), Donal Manahan, William Jaeckle, Saeid Nourizadeh
Ontogenic Changes In The Rates Of Amino Acid Transport From Seawater By Marine Invertebrate Larvae (Echinodermata, Echiura, Mollusca), Donal Manahan, William Jaeckle, Saeid Nourizadeh
William Jaeckle
Transport rates of amino acids were determined for larvae of different ages of the echiuran worm Urechis caupo, the gastropod Haliotis rufescens, the bivalve Crassostrea gigas, and the sea urchin Strongylocentrotus purpuratus. All larval forms showed an increase in the transport rate of amino acids during development. Trochophores of U. caupo increased their rate of net flux for each of 5 amino acids (100 nM each) by a factor of 1.6 and 2.2 during 1-3 days and 4-8 days, respectively, for two independent cultures. In H. rufescens, the maximum transport capacity (Jmax) for alanine increased 3-fold during the 24 h …