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Carlos A. Santamaria - One of the best experts on this subject based on the ideXlab platform.
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Molecular taxonomy of endemic coastal Ligia isopods from the Hawaiian Islands: re-description of L. hawaiensis and description of seven novel cryptic species.
PeerJ, 2019Co-Authors: Carlos A. SantamariaAbstract:Past phylogeographic work has shown Ligia hawaiensis, a coastal isopod species endemic to the Hawaiian Islands, to be a paraphyletic complex of several highly genetically divergent yet morphologically cryptic lineages. Despite the need for a taxonomic revision of this species, the lack of morphological differentiation has proven an impediment to formally describe new Ligia species in the region. Molecular characters and species delimitation approaches have been successfully used to formally describe cryptic species in other crustacean taxa, suggesting they may aid taxonomic revisions of L. hawaiensis. Herein, various distance- and tree-based molecular species delimitation approaches are applied on a concatenated dataset comprised of both mitochondrial and nuclear gene sequences of L. hawaiensis and L. perkinsi, a terrestrial species endemic to the Hawaiian archipelago. Results of these analyses informed a taxonomic revision leading to the redescription of L. hawaiensis and the description of seven new cryptic species on the basis of molecular characters: L. dante, L. eleluensis, L. honu, L. kamehameha, L. mauinuiensis, L. pele, and L. rolliensis. These coastal Ligia species from the Hawaiian archipelago appear to be largely limited to single islands, where they appear largely constrained to volcanic rift zones suggesting allopatric events at local scales may drive diversification for poorly dispersing organisms in the Hawaiian coastlines. Additional work remains needed to fully assess the role of said events; however, the description of these novel species underscore their potential to aid in studies of local diversification of marine organisms in Hawai'i. Lastly, this represents the first application of molecular taxonomic approaches to formally describe genetic lineages found in Ligia isopods as species, underscoring the promise these methods hold to taxonomic revisions in other species in the genus shown to harbor cryptic genetic lineages.
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Molecular approaches uncover cryptic diversity in intertidal Ligia isopods (Crustacea, Isopoda, Ligiidae) across the southern Africa coastline
PeerJ, 2018Co-Authors: Taylor M. Greenan, Charles L. Griffiths, Carlos A. SantamariaAbstract:Recent phylogeographic studies along the coastline of southern Africa have uncovered cryptic diversity in several coastal invertebrates, including direct developing crustaceans in the superorder Peracarida. These findings indicating the possible existence of additional cryptic diversity in other yet to be studied peracarids, particularly those known to harbor said cryptic diversity in other regions of the world. Isopods in the genus Ligia are one such taxon. They inhabit patchy rocky beaches, are direct developers, avoid the open water, and exhibit other biological traits that severely constrain their dispersal potential (e.g., poor desiccation resistance). These traits are thought to have led to long-term isolation of populations, and allopatric diversification in Ligia species around the world; however, Ligia species in southern Africa, where three endemic Ligia species of uncertain validity are known to exist, remain unstudied to date. In this study, we used mitochondrial and nuclear markers to characterize Ligia collected in 18 localities from Namibia to the KwaZulu-Natal region of South Africa. We report the presence of cryptic lineages within Ligia species in the region that suggest the need for taxonomic reevaluation of these isopod species.
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Phylogeography and cryptic diversity of intertidal Ligia isopods (Crustacea, Isopoda, Ligiidae) across the southern Africa coastline
2017Co-Authors: Taylor M. Greenan, Charles L. Griffiths, Carlos A. SantamariaAbstract:The extensive coastlines of South Africa and Namibia extends from the Atlantic to the Indian Ocean and encompass several major biogeographic provinces, each characterized by unique faunal and floral assemblages. Recent biogeographic studies have led to competing biogeographic models of the southern African coastline. This has stimulated phylogeographic work to determine whether the distribution of genetic diversity within coastal invertebrate species match the proposed biogeographic regions. The lack of congruence between studies and the discovery of cryptic diversity indicating the possible existence of cryptic species in coastal isopods in the region underscore the need for additional phylogeographic research in southern Africa, particularly for organisms that have been shown to both harbor cryptic diversity and to retain signatures of past geological and oceanographic processes in their phylogeographic patterns. Isopods in the genus Ligia exhibit several biological traits that suggest they may be informative on phylogeographic patterns. They inhabit patchy rocky beaches, are direct developers, avoid the open water, and exhibit several biological traits that severely constrain their dispersal potential (e.g. poor desiccation resistance). These traits are thought to lead to long term isolation of populations, the retention of geological and oceanographic signatures in phylogeographic patterns of Ligia, and the presence of cryptic lineages. In this study, we used mitochondrial and nuclear markers to characterize Ligia collected in 18 localities across Namibia to the KwaZulu-Natal region of South Africa. We report the presence of cryptic lineages within Ligia species in the region, as well as distributional patterns that differ from those reported from other coastal taxa, but that broadly matches a widely used biogeographic model for the region.
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Cryptic biodiversity and phylogeographic patterns of Seychellois Ligia isopods.
PeerJ, 2017Co-Authors: Carlos A. Santamaria, Joanna K. Bluemel, Nancy Bunbury, Melinda CurranAbstract:Ligia isopods are conspicuous inhabitants of rocky intertidal habitats exhibiting several biological traits that severely limit their dispersal potential. Their presence in patchy habitats and low vagility may lead to long term isolation, allopatric isolation and possible cryptic speciation. Indeed, various species of Ligia have been suggested to represent instead cryptic species complexes. Past studies; however, have largely focused in Eastern Pacific and Atlantic species of Ligia, leaving in doubt whether cryptic diversity occurs in other highly biodiverse areas. The Seychelles consists of 115 islands of different ages and geological origins spread across the western Indian Ocean. They are well known for their rich biodiversity with recent reports of cryptic species in terrestrial Seychellois organisms. Despite these studies, it is unclear whether coastal invertebrates from the Seychelles harbor any cryptic diversity. In this study, we examined patterns of genetic diversity and isolation within Ligia isopods across the Seychelles archipelago by characterizing individuals from locations across both inner and outer islands of the Seychelles using mitochondrial and nuclear markers. We report the presence of highly divergent lineages of independent origin. At Aldabra Atoll, we uncovered a lineage closely related to the Ligia vitiensis cryptic species complex. Within the inner islands of Cousine, Silhouette, and Mahe we detected the presence of two moderately divergent and geographically disjunct lineages most closely related to Ligia dentipes. Our findings suggest that the Seychelles may harbor at least three novel species of Ligia in need of description and that these species may have originated independently.
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First record of the Ligia baudiniana species complex in the American Gulf of Mexico Coastline, as confirmed by morphological and molecular approaches.
F1000Research, 2017Co-Authors: Carlos A. Santamaria, Edgar T. Bischoff, Moe Aye, Keith W. Phillips, Victoria OvermeyerAbstract:Ligia isopods exhibit a constrained morphology that makes identification difficult. In the Greater Caribbean, a convoluted taxonomic history has left the distributional limits of Ligia baudiniana unclear. To date, no confirmed records of this species exist from the American Gulf of Mexico. Herein, we report the presence of L. baudiniana in Sarasota-Manatee Florida, as confirmed by morphological and molecular approaches. This is the first record of this species in the region and a ~300Km extension of its range. Specimens were collected in mangroves, underscoring the importance of protecting these habitats.
Hon-cheng Chen - One of the best experts on this subject based on the ideXlab platform.
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Desiccation Resistance of Two Semiterrestrial Isopods, Ligia Exotica and Ligia Taiwanensis (Crustacea) in Taiwan
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 1998Co-Authors: Min-li Tsai, Chang-feng Dai, Hon-cheng ChenAbstract:Abstract The ability to resist desiccation stress was examined in two semiterrestrial Ligia species, Ligia exotica Roux and L. taiwanensis Lee, in Taiwan, under a certain desiccation condition. L. exotica exhibited the longer survival time, lower weight-specific rates of water loss, and the slightly higher ability of tolerance to water loss, compared to L. taiwanensis. In each species, the animal size displays a positive correlation to the survival time and total ability to resist desiccation, yet this size effects on the weight-specific water loss rate is negative. Neither water content nor maximum tolerance to water loss shows the association with the animal size in both species. The path ways and magnitudes of the interactions between these traits of desiccation resistance are analyzed and diagrammed using a stepwise regression model. In this model, the body sizes of animal can explain the most part of the variations in the survival time. The body size has a direct effect and an indirect effect, through the effect on water loss rate, on the time that the experimental animals can survival under this desiccated condition. These results suggest that L. exotica attains larger size than does L. taiwanensis, a lower transpiration rate and, consequently, a greater ability in desiccation resistance. The performances of these interactions in the desiccated resistance are more advantageous for L. exotica to migrate and colonize in variable land habitats within a certain limit, and as a result that L. exotica shows a broader distribution pattern than did L. taiwanensis in Taiwan.
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Responses of Two Semiterrestrial Isopods, Ligia exotica and Ligia taiwanensis (Crustacea) to Osmotic Stress
Comparative Biochemistry and Physiology Part A: Physiology, 1997Co-Authors: Min-li Tsai, Chang-feng Dai, Hon-cheng ChenAbstract:When immersed in fresh water, Ligia taiwanensis is a poorer osmoregulator than Ligia exotica ,a s judged by a lower LD50 at 96 hr and by the osmolalities of haemolymph. Animals appear to osmoregulate more efficiently in air. On immersion, both species displayed hyper- and hypo-osmoregulatory ability. Both species subjected less osmotic selection pressure during their inland colonization. The results suggest that a route of terrestrial colonization not involving transitional freshwater stresses had been taken by L. exotica and L. taiwa- nensis. comp biochem physiol 118A;1:141-146, 1997. © 1997 Elsevier Science Inc.
Min-li Tsai - One of the best experts on this subject based on the ideXlab platform.
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Desiccation Resistance of Two Semiterrestrial Isopods, Ligia Exotica and Ligia Taiwanensis (Crustacea) in Taiwan
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 1998Co-Authors: Min-li Tsai, Chang-feng Dai, Hon-cheng ChenAbstract:Abstract The ability to resist desiccation stress was examined in two semiterrestrial Ligia species, Ligia exotica Roux and L. taiwanensis Lee, in Taiwan, under a certain desiccation condition. L. exotica exhibited the longer survival time, lower weight-specific rates of water loss, and the slightly higher ability of tolerance to water loss, compared to L. taiwanensis. In each species, the animal size displays a positive correlation to the survival time and total ability to resist desiccation, yet this size effects on the weight-specific water loss rate is negative. Neither water content nor maximum tolerance to water loss shows the association with the animal size in both species. The path ways and magnitudes of the interactions between these traits of desiccation resistance are analyzed and diagrammed using a stepwise regression model. In this model, the body sizes of animal can explain the most part of the variations in the survival time. The body size has a direct effect and an indirect effect, through the effect on water loss rate, on the time that the experimental animals can survival under this desiccated condition. These results suggest that L. exotica attains larger size than does L. taiwanensis, a lower transpiration rate and, consequently, a greater ability in desiccation resistance. The performances of these interactions in the desiccated resistance are more advantageous for L. exotica to migrate and colonize in variable land habitats within a certain limit, and as a result that L. exotica shows a broader distribution pattern than did L. taiwanensis in Taiwan.
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Responses of Two Semiterrestrial Isopods, Ligia exotica and Ligia taiwanensis (Crustacea) to Osmotic Stress
Comparative Biochemistry and Physiology Part A: Physiology, 1997Co-Authors: Min-li Tsai, Chang-feng Dai, Hon-cheng ChenAbstract:When immersed in fresh water, Ligia taiwanensis is a poorer osmoregulator than Ligia exotica ,a s judged by a lower LD50 at 96 hr and by the osmolalities of haemolymph. Animals appear to osmoregulate more efficiently in air. On immersion, both species displayed hyper- and hypo-osmoregulatory ability. Both species subjected less osmotic selection pressure during their inland colonization. The results suggest that a route of terrestrial colonization not involving transitional freshwater stresses had been taken by L. exotica and L. taiwa- nensis. comp biochem physiol 118A;1:141-146, 1997. © 1997 Elsevier Science Inc.
Luis A. Hurtado - One of the best experts on this subject based on the ideXlab platform.
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Isopods of the genus Ligia as potential biomonitors of trace metals from the gulf of California and pacific coast of the Baja California peninsula.
Ecotoxicology and environmental safety, 2014Co-Authors: Jaqueline García-hernández, Luis A. Hurtado, Germán N. Leyva-garcía, Adrián Güido-moreno, Daniela Aguilera-márquez, Veronica Mazzei, Margherita FerranteAbstract:Supralittoral and high intertidal coastal zones are exposed to pollution from both marine and terrestrial sources and undergo higher deposition rates than the subtidal zone. It is therefore important to identify organisms for this section of the coastal area that can be tolerant to contaminants. The aim of this study was to determine if supralittoral isopods of the genus Ligia can be used as biomonitors, since they are abundant and widely distributed. For this purpose, concentrations of trace elements were determined in Ligia isopods in toto from 26 locations across the Gulf of California and Pacific coast of the Baja California peninsula, which were collected during the summers of 2009 and 2010. The concentrations of trace elements followed the order of; Zn≥Cu>As>Cd>Pb>Hg. Elevated concentrations of copper (up to 1010 μg/g) were detected in Ligia from Santa Rosalia (SRo), a locality where industrial mining of copper has historically occurred. Industrial and municipal sewage discharges appear to have contributed to the high concentrations of zinc (326 μg/g) and lead (144 μg/g) found in organisms from Guaymas location. The high mercury concentration in organisms from Mazatlan (M) (2.01 μg/g) was associated with a thermoelectric plant. Natural sources of metals were also detected; coastal upwelling appears to be associated with high cadmium concentrations in Ligia from Punta Baja (PB) (256 μg/g) in the Pacific coast, whereas hydrothermal vents may have contributed to high concentrations of arsenic at Ensenada (E) (61 μg/g). Our results suggest that Ligia isopods reflect the natural and anthropogenic inputs of trace metals in the environment and could potentially be used as biomonitor organisms of the intertidal rocky shores of the Gulf of California and Pacific coast.
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Diversification at the narrow sea-land interface in the Caribbean: phylogeography of endemic supralittoral Ligia isopods
Frontiers in Ecology and Evolution, 2014Co-Authors: Carlos A. Santamaria, Mariana Mateos, Luis A. HurtadoAbstract:Phylogeographic studies have provided valuable insights into the evolutionary histories and biodiversity of different groups in the Caribbean, a region that harbors exceptional terrestrial and marine biodiversity. Herein, we examined phylogeographic patterns of the poorly dispersing supralittoral isopod Ligia sampled from 35 localities in the Caribbean Sea and adjacent areas, as well as from Veracruz (Gulf of Mexico), the type locality of L. baudiniana (the only currently recognized native Ligia species in the Caribbean). We conducted Maximum Likelihood and Bayesian phylogenetic analyses of four mitochondrial genes (Cytb, 16S rDNA, 12S rDNA and COI) and Parsimony analyses of one nuclear gene (NaK). We found a well-supported and highly divergent clade of Ligia that is distributed in the Caribbean Sea, Bahamas, southern Florida, Bermuda, and the Pacific coast of Central America and Colombia, but not in the Gulf of Mexico. A characteristic appendix masculina distinguishes this clade from other lineages of Ligia. Large divergences within this clade suggest that it constitutes a cryptic species complex. Genetically and morphologically, the specimens from the type locality of L. baudiniana were indistinguishable from the non-native species L. exotica. Some phylogeographic patterns of Ligia in the study area may be consistent with the proto-Antillean or GAARlandia vicariant hypotheses, but uncertainty concerning divergence times and aspects of the geological history precludes stronger biogeographical inferences. Passive overwater dispersal appears to have played an important role in shaping phylogeographic patterns of Ligia in the Caribbean Sea. These patterns, however, do not correspond with predicted biogeographic patterns based on population connectivity of marine organisms with larval dispersal, and do not reflect the southeast to northwest colonization pattern that has been proposed for the colonization of the Caribbean from South America by some terrestrial animals.
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A complex evolutionary history in a remote archipelago: phylogeography and morphometrics of the Hawaiian endemic Ligia isopods.
PloS one, 2013Co-Authors: Carlos A. Santamaria, Mariana Mateos, Stefano Taiti, Thomas J. Dewitt, Luis A. HurtadoAbstract:Compared to the striking diversification and levels of endemism observed in many terrestrial groups within the Hawaiian Archipelago, marine invertebrates exhibit remarkably lower rates of endemism and diversification. Supralittoral invertebrates restricted to specific coastal patchy habitats, however, have the potential for high levels of allopatric diversification. This is the case of Ligia isopods endemic to the Hawaiian Archipelago, which most likely arose from a rocky supralittoral ancestor that colonized the archipelago via rafting, and diversified into rocky supralittoral and inland lineages. A previous study on populations of this isopod from Oʻahu and Kauaʻi revealed high levels of allopatric differentiation, and suggested inter-island historical dispersal events have been rare. To gain a better understanding on the diversity and evolution of this group, we expanded prior phylogeographic work by incorporating populations from unsampled main Hawaiian Islands (Maui, Molokaʻi, Lanaʻi, and Hawaiʻi), increasing the number of gene markers (four mitochondrial and two nuclear genes), and conducting Maximum likelihood and Bayesian phylogenetic analyses. Our study revealed new lineages and expanded the distribution range of several lineages. The phylogeographic patterns of Ligia in the study area are complex, with Hawaiʻi, Oʻahu, and the Maui-Nui islands sharing major lineages, implying multiple inter-island historical dispersal events. In contrast, the oldest and most geographically distant of the major islands (Kauaʻi) shares no lineages with the other islands. Our results did not support the monophyly of all the supralittoral lineages (currently grouped into L. hawaiensis), or the monophyly of the terrestrial lineages (currently grouped into L. perkinsi), implying more than one evolutionary transition between coastal and inland forms. Geometric-morphometric analyses of three supralittoral clades revealed significant body shape differences among them. A taxonomic revision of Hawaiian Ligia is warranted. Our results are relevant for the protection of biodiversity found in an environment subject to high pressure from disturbances.
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Phylogeography of supralittoral rocky intertidal Ligia isopods in the pacific region from central California to central Mexico.
PloS one, 2010Co-Authors: Luis A. Hurtado, Mariana Mateos, Carlos A. SantamariaAbstract:Background Ligia isopods are widely distributed in the Pacific rocky intertidal shores from central California to central Mexico, including the Gulf of California. Yet, their biological characteristics restrict them to complete their life cycles in a very narrow range of the rocky intertidal supralittoral. Herein, we examine phylogeographic patterns of Ligia isopods from 122 localities between central California and central Mexico. We expect to find high levels of allopatric diversity. In addition, we expect the phylogeographic patterns to show signatures of past vicariant events that occurred in this geologically dynamic region. Methodology/Principal Findings We sequenced two mitochondrial genes (Cytochrome Oxidase I and 16S ribosomal DNA). We conducted Maximum Likelihood and Bayesian phylogenetic analyses. We found many divergent clades that, in general, group according to geography. Some of the most striking features of the Ligia phylogeographic pattern include: (1) deep mid-peninsular phylogeographic breaks on the Pacific and Gulf sides of Baja peninsula; (2) within the Gulf lineages, the northern peninsula is most closely related to the northern mainland, while the southern peninsula is most closely related to the central-southern mainland; and, (3) the southernmost portion of the peninsula (Cape Region) is most closely related to the southernmost portion of mainland. Conclusions/Significance Our results shed light on the phylogenetic relationships of Ligia populations in the study area. This study probably represents the finest-scale phylogeographic examination for any organism to date in this region. Presence of highly divergent lineages suggests multiple Ligia species exist in this region. The phylogeographic patterns of Ligia in the Gulf of California and Baja peninsula are incongruent with a widely accepted vicariant scenario among phylogeographers, but consistent with aspects of alternative geological hypotheses and phylo- and biogeographic patterns of several other taxa. Our findings contribute to the ongoing debate regarding the geological origin of this important biogeographic region.
Thomas H Carefoot - One of the best experts on this subject based on the ideXlab platform.
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microhabitat preferences of young Ligia pallasii brandt
2016Co-Authors: Thomas H CarefootAbstract:greater turning frequency in response to high humidity (Carthy, 1958). The semi-terrestrial "sea slater", Ligia pallasii Brandt, 1833, also exhibits this tendency. This species lives in sea-cliff habitats on the northeast Pacific coast, generally from the highest tide mark to 2-3 m above this level. The adult and maturing stages occupy a microhabitat of moist crannies, particularly where fresh water seeps through the rocks, while animals newly emerged from the brood pouch favour microhabitats of moist seaweed. In the study area of Port Renfrew, British Colum bia, Canada (see Carefoot, 1973a for a description of the habitat), young Ligia are found in growths of the green seaweed, Enteromorpha sp. As a result of permanent seepage of fresh water this alga grows luxuriantly in runnels at the high tide mark and slightly above. Other seaweeds, such as Cladophora sp., Rhodomela larix (Turner) C. Agardh, Endocladia muricata (Harvey) J. Agardh, and Scytosiphon lomentaria (Lyngbye) J. Agardh, grow around tidepools about 1-2 m below the upper limit of Enteromorpha growth. None of these lower sea weeds host populations of young Ligia. In this study, I have examined the microhabitat preferences of young Ligia in an attempt to explain their field preference for Enteromorpha and have discussed the significance of the change in habitat in the animal's life cycle. MATERIALS AND METHODS Young Ligia, of a length of 4-5 mm (from anterior margin of cephalon to tip of telson), were collected from beds of moist Enteromorpha. A flat, metal spatula was used to gently transfer the animals from the seaweed to small glass vials. These animals were used as soon as possible after collection in experiments designed to test their preference for certain microhabitat characteristics or sub strate types. The experiments were performed in a field laboratory as follows: glass "finger" bowls (20 cm dia.), lined with paper towelling moistened with freshwater, were used as the test chambers. Test conditions were established in each chamber as, for example, by placing two equal-sized clumps of freshly col 14
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terrestrial life in isopods evolutionary loss of gas exchange and survival capability in water
Canadian Journal of Zoology, 1993Co-Authors: Barbara E Taylor, Thomas H CarefootAbstract:Survival and oxygen uptake in air and water were investigated in four species of terrestrial isopods, Armadillidium vulgare Latreille, 1804, Porcellio scaber Latreille, 1804, Oniscus asellus Linne, 1758, and Ligia pallasii Brandt, 1833, to compare the degree of vestigial adaptation to aquatic existence versus adaptation to terrestrial existence. Most submerged A. vulgare, P. scaber, and O. asellus died by 18 h, whether in fresh water or isosmotic seawater. Ligia pallasii lived for almost 2 d in fresh water and for at least 25 d in seawater (none died during this time). Oxygen uptake in water was 44 – 66% that in air for the three fully terrestrial species, and 160% that in air for the semiterrestrial L. pallasii. Oxygen consumption of submerged A. vulgare (representative of fully terrestrial forms) declined to 50% after 14 h and to 17% by 24 h, by which time the animals were clinically dead. In comparison, L. pallasii's aquatic oxygen consumption was maintained at normal or higher levels for at least 3 d....
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Effect of dietary d-amino acids on growth, survival, ammonia excretion and specific dynamic action in the supralittoral isopod, Ligia pallasii
Comparative Biochemistry and Physiology Part A: Physiology, 1992Co-Authors: Thomas H Carefoot, Barbara E Taylor, Sabine Kalwa, George Somogyi, Barbara HughesAbstract:Abstract 1. 1. Growth, survival, ammonia excretion and Specific Dynamic Action (SDA) were assessed in the supralittoral isopod Ligia pallasii eating chemical diets with differing proportions of d - and l -amino acids. Growth and survival decreased in direct proportion to increasing dietary intake of d -amino acids. 2. 2. Survival on diets with greater than 50% content of d -amino acids (based on total amino acids in diet) was lower than that expected based on previous work, suggesting a deleterious effect of the d -isomers. 3. 3. Ammonia excretion and SDA correlated negatively with increasing dietary content of d -amino acids. 4. 4. The general conclusion is that d -amino acids play no role in anabolic or energy metabolism in Ligia , and that poor performance at higher dietary levels of d -amino acids may relate to their interference with transport pathways for the normal l -forms.
