The Biological bulletin最新文献

{"title":"Functional and Evolutionary Implications of Opposed Bands, Big Mouths, and Extensive Oral Ciliation in Larval Opheliids and Echiurids (Annelida).","authors":"B G Miner,&nbsp;E Sanford,&nbsp;R R Strathmann,&nbsp;B Pernet,&nbsp;R B Emlet","doi":"10.2307/1542993","DOIUrl":"https://doi.org/10.2307/1542993","url":null,"abstract":"<p><p>Larvae of two annelids, the opheliid Armandia brevis and the echiurid Urechis caupo, captured small particles between opposed prototrochal and metatrochal ciliary bands and also captured large particles with wide ciliated mouths. The body volume of larval A. brevis increased more rapidly than the estimated maximum clearance rate as segments were added. Capture of larger particles by late-stage larvae may compensate for this potentially unfavorable allometry. The existence of larvae that use two feeding mechanisms at once, not previously known in annelids, suggests possible evolutionary routes between larval forms that feed only with opposed bands (e.g., serpulids and oweniids) and those that use complex oral ciliature to feed primarily on large particles (e.g., polynoids and nephtyids). In particular, the metatroch and food groove of opposed-band feeders may have arisen as expansions of oral ciliation in ancestral large-particle feeders; alternatively, extensive oral ciliation in large-particle feeders may have originated as a modification of metatroch and food-groove cilia in ancestral opposed-band feeders.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"14-25"},"PeriodicalIF":1.6,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542993","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioluminescence in the Deep-Sea Cirrate Octopod Stauroteuthis syrtensis Verrill (Mollusca: Cephalopoda).","authors":"S Johnsen,&nbsp;E J Balser,&nbsp;E C Fisher,&nbsp;E A Widder","doi":"10.2307/1542994","DOIUrl":"https://doi.org/10.2307/1542994","url":null,"abstract":"<p><p>The emission of blue-green bioluminescence ({lambda}max = 470 nm) was observed from sucker-like structures arranged along the length of the arms of the cirrate octopod Stauroteuthis syrtensis. Individual photophores either glowed dimly and continuously or flashed on and off more brightly with a period of 1-2 seconds. Examination of the anatomy and ultrastructure of the photophores confirmed that they are modified suckers. During handling, the photophores were unable to attach to surfaces, suggesting that, unlike typical octopod suckers, they have no adhesive function. The oral position of the photophores and the wavelength of peak emission, coupled with the animals' primary postures, suggests that bioluminescence in S. syrtensis may function as a light lure to attract prey.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"26-39"},"PeriodicalIF":1.6,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542994","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology and Epithelial Ion Transport of the Alkaline Gland in the Atlantic Stingray (Dasyatis sabina).","authors":"G M Grabowski,&nbsp;J G Blackburn,&nbsp;E R Lacy","doi":"10.2307/1542999","DOIUrl":"https://doi.org/10.2307/1542999","url":null,"abstract":"<p><p>The alkaline glands are two fluid-filled sacs that lie on the ventral, posterior surface of each kidney in skates and rays. In this study, the morphology, transepithelial ion transport, fluid constituents, and histochemistry of the alkaline glands of the Atlantic stingray, Dasyatis sabina, were investigated. The duct from each gland joined the corresponding vas deferens and the resulting two common ducts emptied into the cloaca. Dark burgundy, aqueous fluid (pH 8.0-8.2) was secreted into the sacs by a simple columnar epithelium with extensive rough endoplasmic reticulum and large secondary lysosomes containing lipofuscin and membrane fragments. Zonulae occludentes were deep (~22 fibrils), reflecting an electrically tight epithelium (732 ohms/cm2). Carbonic anhydrase activity was localized histochemically within the intercellular spaces and less intensely in the mid-basal cytoplasm. In vitro electrophysiology showed that baseline shortcircuit current (Isc, 29.1 {mu}A/cm2) was reduced 67.0% after Cl- removal from the medium. Cl- removal also completely abolished luminal alkalinization (baseline 4.5 +/- 0.7 {mu}Eq of acid/cm2/h). Luminal exposure to the chloridebicarbonate exchange inhibitor, DIDS, reduced Isc by 38%. Simultaneous administration of DIDS and bumetanide (Na+/K+/Cl- cotransport inhibitor) to the serosal side of the tissue caused the Isc to decrease >100%. Serosal exposure to ouabain (Na-K, ATPase inhibitor) decreased Isc 48%, whereas amiloride (sodium ion channel blocker) and acetazolamide (carbonic anhydrase inhibitor) had no statistically significant effect on Isc or alkalinization rates. Taken together the results suggest the presence of apical epithelial bicarbonate exchangers that are chloride or sodium dependent, basal sodium and HCO3- transport, and an Isc that is not totally dependent on Na+-K+ ATPase.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"82-93"},"PeriodicalIF":1.6,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regeneration of Amputated Avian Bone by a Coral Skeletal Implant.","authors":"B Rinkevich,&nbsp;S Ben-Yakir,&nbsp;R Ben-Yakir","doi":"10.2307/1542992","DOIUrl":"https://doi.org/10.2307/1542992","url":null,"abstract":"<p><p>Bone fractures are common in both wild and captive birds (1, 2). Avian bones are thin and brittle and tend to break into fragments or shatter upon a variety of natural events (midair collisions, fights with other animals; ref. 2) or anthropogenic experiences (wounding by gunfire, collisions with cars or fences, encounters with traps, attacks by dogs or cats, etc.; ref. 1). The prospect of full recovery following repair of avian bone fracture is often poor, and the complication rate is high (3). For wild birds, anything less than complete normal function cannot be regarded as successful, and slight malunion or a change in a few degrees of rotation can produce a severe loss of flight function (4). Furthermore, in nomadic species, time is critical because long periods of rehabilitation may prevent the birds from reuniting with their flocks. In experiments with implantation of fragments of skeleton from the coral Stylophora pistillata, we found the implants to be avian osteo-conductive biomaterial, acting as a scaffold for a direct osteoblastic deposition. In the case study presented here, the bird regained complete flight activity within 2 weeks after surgery, with full regeneration of the amputated ulna.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"11-13"},"PeriodicalIF":1.6,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542992","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-Term Culture of Lobster Central Ganglia: Expression of Foreign Genes in Identified Neurons.","authors":"G K Ganter,&nbsp;R Heinrich,&nbsp;R P Bunge,&nbsp;E A Kravitz","doi":"10.2307/1542995","DOIUrl":"https://doi.org/10.2307/1542995","url":null,"abstract":"<p><p>The ventral nerve cords of lobsters (Homarus americanus) can be cultured in vitro for at least 7 weeks. Over this period, neurons maintain their normal electrophysiological features and continue, among other measures of neuronal health, to synthesize RNA and proteins. One application of this culture system is demonstrated: the manipulation of gene expression in identified neurons. After intracellular injection of complementary RNA (cRNA) encoding green fluorescent protein (GFP), the amount of protein product measured by fluorescent confocal microscopy increases for 4 days and then decreases to background by day 10. Thus, translation of the injected message must have increased for 4 days before declining. Moreover, after injection of cRNA encoding {beta}-galactosidase, the levels of enzyme activity were measured using a fluorogenic substrate, revealing a peak of {beta}-galactosidase activity at 6 to 9 days; this activity was still detectable for at least 10 days after injection. Therefore, either GFP or {beta}-galactosidase can be used as an injectable marker, allowing in vivo quantitation of expression in individual cells over time. We measured long-lasting expression of these proteins after a single injection, suggesting that it may be possible to manipulate the levels of expression of any gene of interest.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"40-48"},"PeriodicalIF":1.6,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542995","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Translocation of Photosynthetic Carbon From Two Algal Symbionts to the Sea Anemone Anthopleura elegantissima.","authors":"H P Engebretson,&nbsp;G Muller-Parker","doi":"10.2307/1542998","DOIUrl":"https://doi.org/10.2307/1542998","url":null,"abstract":"<p><p>The intertidal sea anemone Anthopleura elegantissima contains two symbiotic algae, zoochlorellae and zooxanthellae, in the Northern Puget Sound region. Possible nutritional advantages to hosting one algal symbiont over the other were explored by comparing the photosynthetic and carbon translocation rates of both symbionts under different environmental conditions. Each alga translocated 30% of photosynthetically fixed carbon in freshly collected anemones, although zoochlorellae fixed and translocated less carbon than zooxanthellae. The total amount of carbon translocated to the host was equivalent because densities of zoochlorellae were two to three times greater than were densities of zooxanthellae. In A. elegantissima maintained under high and low irradiance (100 and 10 {mu}mol photons/m2/s) at 20{deg}C and 13{deg}C for 21 days, both algae fixed and translocated carbon at greater rates at 20{deg}C (translocation rates: 0.38 pg C /zoochlorella/h; 1.12 pg C /zooxanthella/h) than at 13{deg}C (translocation rates: 0.06 pg C /zoochlorella/h; 0.37 pg C /zooxanthella/h). However, zoochlorellate anemones received 3.5 times less carbon at 20{deg}C than at 13{deg}C because the higher temperature caused a significant reduction in the density of zoochlorellae. Environmental variables, like temperature, that influence the densities of the two symbionts will affect their relative nutritional contribution to the host. Whether these differences in carbon translocation rates of the two algal symbionts affect the ecology of their anemone host awaits further investigation.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"72-81"},"PeriodicalIF":1.6,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542998","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Problem of the Evolution of Sex.","authors":"R J Redfield","doi":"10.2307/1542981","DOIUrl":"https://doi.org/10.2307/1542981","url":null,"abstract":"The unsolved problem of the evolution of sexual reproduction has been almost exclusively in the domain of population genetics. This suggests that new approaches may be fruitful; here I develop a molecular and phylogenetic framework.","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"404-407"},"PeriodicalIF":1.6,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542981","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coalescents, Phylogenies, and Likelihoods.","authors":"J Felsenstein","doi":"10.2307/1542966","DOIUrl":"https://doi.org/10.2307/1542966","url":null,"abstract":"When phylogenies get down below the species level, they turn into coalescents. Individual genetic loci then have genealogies that are, in the absence of recombination, trees. But as one moves along the genome, recombination moves branches and changes the trees, with the result that other loci more than a few kilobases away usually have very different trees. Between species their trees of ancestry are very similar; the difference in their behavior within and between species is an indication that there really is something different, and nonarbitrary, about the species level. When one looks at the problems of estimation involving these trees, one can get overly involved in estimating the tree itself. But the interest in doing so is limited, as there may be a million completely different coalescent trees for different parts of the genome. Furthermore, the number of varying sites available for estimating each is quite limited, so that each is poorly estimated. The solution to this quandary is to realize that the genealogies are generated by a random process of genetic drift, possibly with other evolutionary forces intervening. What we need to know is not the trees themselves, but the parameters of these evolutionary forces and of population structure, such as effective population size, migration rates, population growth rates. The coalescent process defined by J.F.C. Kingman (1, 2) was the foundation of this theory. Coalescent likelihood methods have been developed by two groups, ours and Griffiths and Tavare's. The two approaches use the same statistical methods and models, and differ mostly in the computational methods. The likelihood for a population sample is the sum over all possible genealogies, summing the probability of that genealogy given the parameters, multiplied by the probability of the sample of sequences","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"343-344"},"PeriodicalIF":1.6,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542966","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Concluding Remarks.","authors":"M L Sogin","doi":"10.1086/BBLv196n3p415","DOIUrl":"https://doi.org/10.1086/BBLv196n3p415","url":null,"abstract":"","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"415-416"},"PeriodicalIF":1.6,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/BBLv196n3p415","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organization of Chemically Activated Food Search Behavior in Procambarus clarkii Girard and Orconectes rusticus Girard Crayfishes.","authors":"C Steele,&nbsp;C Skinner,&nbsp;C Steele,&nbsp;P Alberstadt,&nbsp;C Mathewson","doi":"10.2307/1542954","DOIUrl":"https://doi.org/10.2307/1542954","url":null,"abstract":"<p><p>The feeding responses of decapod crustaceans to chemical stimuli have most often been evaluated in terms of one defining act, ignoring the organization of the behavior. To gain greater insight into foraging behavior, we considered the organization of food-search behavior in evaluating the responses of two species of crayfishes to a feeding stimulant. We also examined the effects of food deprivation on the behavioral organization and whether a behavioral dichotomy exists between food search and feeding behavior in these species. Individual crayfish of the species Procambarus clarkii and Orconectes rusticus were presented with infusions of a feeding stimulant consisting of a supernatant leachate of 100 ml water and 1 g of fish flakes. The stimulant was injected with a syringe and small-bore plastic infusion tubing into the center of a behavioral arena 25 cm square and 15 cm deep. Total injection time was 20 s. Experimental groups were presented with either the full-strength leachate (100%) or one of five dilutions: 75%, 50%, 25%, 10%, or 0% (controls) of full-strength. The feeding stimulant was presented either the day after the crayfish were fed or after one week of food deprivation. We analyzed three components of food-search behavior--detection, probing (near-field search), and locomotion (far-field, or distant, search)--recording the order of occurrence and the latency time to initiation for each behavior. When presented with the stimulus following regular feeding, both species responded to concentrations {ge}50% full-strength with probing behavior (near-field search) prior to locomotion, and to concentrations <50% full-strength with locomotion prior to, or even in the absence of, probing. Detection always occurred first. These results indicate that chemical stimuli preferentially activate distant food search in both species and that a behavioral dichotomy exists between food search and feeding behavior. One week of food deprivation had no effect on the organization of food-search behavior in P. clarkii; however, groups of unfed O. rusticus presented with 25% and 10% full-strength concentrations probed prior to locomotion, indicating a change in behavioral organization.</p>","PeriodicalId":153307,"journal":{"name":"The Biological bulletin","volume":" ","pages":"295-302"},"PeriodicalIF":1.6,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1542954","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34814700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}