74 research outputs found
Animal diversity, 4th Ed./ Cleveland P. Hickman, Jr. ; (et al)
No full textxvi, 460 hal. : ill.; 27 cm
Animal diversity, 4th Ed./ Cleveland P. Hickman, Jr. ; (et al)
No full textxvi, 460 hal. : ill.; 27 cm
Evolutionary responses of marine invertebrates to insular isolation in Galapagos
Get PDFI examine the natural barriers to distribution and colonization that have shaped the Galapagos marine invertebrate biota. While diversity is high for some groups, such as hydroids and bryozoans, it is low for many others. Porcelain crabs and molluscs are examples with reduced or unbalanced representation in Galapagos, resulting from their dependency on dispersal of relatively short-lived planktonic larvae by ocean currents and on habitat limitations in Galapagos. Because Galapagos shorelines are predominantly rocky, without the wide expanses of silt typical of much of the Ecuadorian mainland that are favored by infaunal bivalves, gastropod diversity in Galapagos far exceeds that of bivalves. Nearly all hermatypic corals in Galapagos are members of the Panamic province; none is endemic to Galapagos. This suggests that colonization occurred by larval dispersal from there. The ahermatypic (azooxanthellate) coral fauna of Galapagos, with 43 species, is richer and more diverse than the hermatypic corals, with 29% of the shallow-water ahermatypes endemic and the remainder with Panamic, Indo-Pacific, and cosmopolitan affinities. The 73 verified species of Galapagos shallow-water echinoderms are dominated by Panamic species, with additional affinities to the Indo-Pacific and the California province; 8% are cosmopolitan and 8% endemic. With species richness roughly equivalent to that of Pacific Colombia, Galapagos echinoderm representation is not depauperate, but is sufficiently distinctive to characterize it as an isolated, insular biota. Hydroids and bryozoans, two groups with high diversity in Galapagos, accomplish long-distance transport mainly as adults on floating debris and hulls of ships, rather than by the free-swimming reproductive stage. Endemism among marine invertebrates averages 18.3 %, but varies widely among major taxa, from 0% for reef corals to 71% for gorgonians. Unlike the Galapagos terrestrial biota, in which endemic genera are common, the absence of endemic genera among marine invertebrates may be attributed to low isolation arising from greater dispersal and gene flow in the marine environment
Evolutionary responses of marine invertebrates to insular isolation in Galapagos
No full textI examine the natural barriers to distribution and colonization that have shaped the Galapagos marine invertebrate biota. While diversity is high for some groups, such as hydroids and bryozoans, it is low for many others. Porcelain crabs and molluscs are examples with reduced or unbalanced representation in Galapagos, resulting from their dependency on dispersal of relatively short-lived planktonic larvae by ocean currents and on habitat limitations in Galapagos. Because Galapagos shorelines are predominantly rocky, without the wide expanses of silt typical of much of the Ecuadorian mainland that are favored by infaunal bivalves, gastropod diversity in Galapagos far exceeds that of bivalves. Nearly all hermatypic corals in Galapagos are members of the Panamic province; none is endemic to Galapagos. This suggests that colonization occurred by larval dispersal from there. The ahermatypic (azooxanthellate) coral fauna of Galapagos, with 43 species, is richer and more diverse than the hermatypic corals, with 29% of the shallow-water ahermatypes endemic and the remainder with Panamic, Indo-Pacific, and cosmopolitan affinities. The 73 verified species of Galapagos shallow-water echinoderms are dominated by Panamic species, with additional affinities to the Indo-Pacific and the California province; 8% are cosmopolitan and 8% endemic. With species richness roughly equivalent to that of Pacific Colombia, Galapagos echinoderm representation is not depauperate, but is sufficiently distinctive to characterize it as an isolated, insular biota. Hydroids and bryozoans, two groups with high diversity in Galapagos, accomplish long-distance transport mainly as adults on floating debris and hulls of ships, rather than by the free-swimming reproductive stage. Endemism among marine invertebrates averages 18.3 %, but varies widely among major taxa, from 0% for reef corals to 71% for gorgonians. Unlike the Galapagos terrestrial biota, in which endemic genera are common, the absence of endemic genera among marine invertebrates may be attributed to low isolation arising from greater dispersal and gene flow in the marine environment
Integrated principles of zoology / Cleveland P. Hickman, Jr., Larry S. Roberts, Frances M. Hickman
No full textPreliminary survey of zooxanthellate zoanthids (Cnidaria : Hexacorallia) of the Galapagos, and associated symbiotic dinoflagellates (Symbiodinium spp.)
No full textDespite their presence in almost all marine ecosystems, the zoanthids (Cnidaria: Hexacorallia: Zoantharia) are poorly studied, in large part due to a lack of useful morphological identification characters. Recent research combining morphology with DNA markers has begun to shed new light on diversity and distribution of the order Zoantharia. Here, preliminary findings on the diversity and distribution of zooxanthellate zoanthid species from the genera Zoanthus and Palythoa are presented, documenting these genera in the Galapagos for the first time. A brief description of the species found is provided. Zoanthus and Palythoa appear to be limited in the Galapagos to rocky shores in warm shallow sublittoral and infralittoral waters (minimum temperature >18°C), isolated from the colder water that dominates much of the archipelago. Preliminary results from the internal transcribed spacer region of ribosomal DNA sequences of symbiotic dinoflagellates suggest that both Zoanthus and Palythoa spp. in the Galapagos possess only Symbiodinium clade C. Brief descriptions of the zooxanthellate zoanthid species found in the Galapagos are provided
TRANSFORMATION REACTIONS AND SPONTANEOUS LABELLING OF IODOPHENOLS DURING THIN-LAYER CHROMATOGRAPHY OF RADIOIODINE <sup>125</sup>I
No full textBinding of Inorganic Iodide to the Plasma Proteins of Teleost Fishes
No full text The natural binding of inorganic iodide by plasma proteins was studied in 10 freshwater teleost fishes, 16 marine teleost fishes, 3 elasmobranchs, 1 amphibian, 1 reptile, 1 bird, 2 mammals, and 2 arthropods. Of these, significant binding existed only in species of the order Clupeiformes including Esox lucius (average 80.9% of plasma inorganic iodide was protein-bound at 20 C), Coregonus clupeaformis (average 80.3% bound), Salmo gairdneri (average 84.3% bound), and Thymallus arcticus (average 81.0% bound). Significant binding was not found in fish of the orders Cypriniformes, Perciformes, Pleuronectiformes, Batrachoidiformes, Gadiformes, Squaliformes, Chimaeriformes, and Rajiformes. Esox lucius and C. clupeaformis showed a small seasonal variation in binding capacity. The plasma of male fish bound significantly more iodide than did the plasma of female fish.Inorganic iodide was found to bind with a plasma albumin-like protein. The binding sites were presumably free cationic groups of basic amino acid residues on the protein molecules. Iodide binding was inhibited by NO3−, SCN−, ClO4−, and CCl3COO−, but not affected by thiourea, thiouracil, and other halide ions. Binding energy was weak in both E. lucius (−5.98 Kcal/mole) and C. clupeaformis (−6.08 Kcal/mole). </jats:p
The Effect of Physical Conditioning on the Metabolism of Lactate, Phosphate, and Glucose in Rainbow Trout, <i>Salmo gairdneri</i>
No full text Physiological effects of physical conditioning to water current were studied on three groups of [Formula: see text]-year-old rainbow trout, Salmo gairdneri, acclimated to 4 C. Group one (control) was raised in still water. Groups two and three were conditioned to water velocities of 20 cm/sec and 40 cm/sec, respectively, for 16 days before sampling. Muscle and plasma samples were collected before exercise and four times during subjection to 15 min of forced swimming at 53.4 cm/sec and eight times during a 24-hr recovery period. Conditioning significantly delayed the point of fatigue during forced exercise: the unconditioned fish were fatigued after about 5 min swimming, group two after about 10 min swimming, and group three at about 15 min.Physically conditioned trout showed significantly higher muscle and plasma lactate levels when fatigued, and more rapid removal of lactate from muscle and plasma during recovery from fatigue, than unconditioned trout. Exercise resulted in parallel oscillating concentration fluctuations of tissue phosphate and significant increases in concentrations of plasma phosphate in both conditioned and unconditioned fish. Plasma glucose showed no significant change during exercise but rose slightly during the recovery of all groups. </jats:p
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