The Extent Of Introgression Outside The Contact Zone Between Notropis Cornutus And Notropis Chrysocephalus (Teleostei: Cyprinidae)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137435/1/evo04362.pd

Evolution of sex-dependent mtDNA transmission in freshwater mussels (Bivalvia: Unionida)

Doubly uniparental inheritance (DUI) describes a mode of mtDNA transmission widespread in gonochoric freshwater mussels (Bivalvia: Palaeoheterodonta: Unionida). In this system, both female- and male-transmitted mtDNAs, named F and M respectively, coexist in the same species. In unionids, DUI is strictly correlated to gonochorism and to the presence of the atypical open reading frames (ORFans) F-orf and M-orf, respectively inside F and M mtDNAs, which are hypothesized to participate in sex determination. However, DUI is not found in all three Unionida superfamilies (confirmed in Hyrioidea and Unionoidea but not in Etherioidea), raising the question of its origin in these bivalves. To reconstruct the co-evolution of DUI and of ORFans, we sequenced the mtDNAs of four unionids (two gonochoric with DUI, one gonochoric and one hermaphroditic without DUI) and of the related gonochoric species Neotrigonia margaritacea (Palaeoheterodonta: Trigoniida). Our analyses suggest that rearranged mtDNAs appeared early during unionid radiation, and that a duplicated and diverged atp8 gene evolved into the M-orf associated with the paternal transmission route in Hyrioidea and Unionoidea, but not in Etherioidea. We propose that novel mtDNA-encoded genes can deeply influence bivalve sex determining systems and the evolution of the mitogenomes in which they occur

Widespread and persistent invasions of terrestrial habitats coincident with larval feeding behavior transitions during snail-killing fly evolution (Diptera: Sciomyzidae)

BACKGROUND: Transitions in habitats and feeding behaviors were fundamental to the diversification of life on Earth. There is ongoing debate regarding the typical directionality of transitions between aquatic and terrestrial habitats and the mechanisms responsible for the preponderance of terrestrial to aquatic transitions. Snail-killing flies (Diptera: Sciomyzidae) represent an excellent model system to study such transitions because their larvae display a range of feeding behaviors, being predators, parasitoids or saprophages of a variety of mollusks in freshwater, shoreline and dry terrestrial habitats. The remarkable genus Tetanocera (Tetanocerini) occupies five larval feeding groups and all of the habitat types mentioned above. This study has four principal objectives: (i) construct a robust estimate of phylogeny for Tetanocera and Tetanocerini, (ii) estimate the evolutionary transitions in larval feeding behaviors and habitats, (iii) test the monophyly of feeding groups and (iv) identify mechanisms underlying sciomyzid habitat and feeding behavior evolution. RESULTS: Bayesian inference and maximum likelihood analyses of molecular data provided strong support that the Sciomyzini, Tetanocerini and Tetanocera are monophyletic. However, the monophyly of many behavioral groupings was rejected via phylogenetic constraint analyses. We determined that (i) the ancestral sciomyzid lineage was terrestrial, (ii) there was a single terrestrial to aquatic habitat transition early in the evolution of the Tetanocerini and (iii) there were at least 10 independent aquatic to terrestrial habitat transitions and at least 15 feeding behavior transitions during tetanocerine phylogenesis. The ancestor of Tetanocera was aquatic with five lineages making independent transitions to terrestrial habitats and seven making independent transitions in feeding behaviors. CONCLUSIONS: The preponderance of aquatic to terrestrial transitions in sciomyzids goes against the trend generally observed across eukaryotes. Damp shoreline habitats are likely transitional where larvae can change habitat but still have similar prey available. Transitioning from aquatic to terrestrial habitats is likely easier than the reverse for sciomyzids because morphological characters associated with air-breathing while under the water\u27s surface are lost rather than gained, and sciomyzids originated and diversified during a general drying period in Earth\u27s history. Our results imply that any animal lineage having aquatic and terrestrial members, respiring the same way in both habitats and having the same type of food available in both habitats could show a similar pattern of multiple independent habitat transitions coincident with changes in behavioral and morphological traits

Mitochondrial phylogenomics of the Bivalvia (Mollusca): searching for the origin and mitogenomic correlates of doubly uniparental inheritance of mtDNA

<p>Abstract</p> <p>Background</p> <p>Doubly uniparental inheritance (DUI) is an atypical system of animal mtDNA inheritance found only in some bivalves. Under DUI, maternally (F genome) and paternally (M genome) transmitted mtDNAs yield two distinct gender-associated mtDNA lineages. The oldest distinct M and F genomes are found in freshwater mussels (order Unionoida). Comparative analyses of unionoid mitochondrial genomes and a robust phylogenetic framework are necessary to elucidate the origin, function and molecular evolutionary consequences of DUI. Herein, F and M genomes from three unionoid species, <it>Venustaconcha ellipsiformis, Pyganodon grandis </it>and <it>Quadrula quadrula </it>have been sequenced. Comparative genomic analyses were carried out on these six genomes along with two F and one M unionoid genomes from GenBank (F and M genomes of <it>Inversidens japanensis </it>and F genome of <it>Lampsilis ornata</it>).</p> <p>Results</p> <p>Compared to their unionoid F counterparts, the M genomes contain some unique features including a novel localization of the <it>trnH </it>gene, an inversion of the <it>atp8-trnD </it>genes and a unique 3'coding extension of the cytochrome <it>c </it>oxidase subunit II gene. One or more of these unique M genome features could be causally associated with paternal transmission. Unionoid bivalves are characterized by extreme intraspecific sequence divergences between gender-associated mtDNAs with an average of 50% for <it>V. ellipsiformis</it>, 50% for <it>I. japanensis</it>, 51% for <it>P. grandis </it>and 52% for <it>Q. quadrula </it>(uncorrected amino acid p-distances). Phylogenetic analyses of 12 protein-coding genes from 29 bivalve and five outgroup mt genomes robustly indicate bivalve monophyly and the following branching order within the autolamellibranch bivalves: ((Pteriomorphia, Veneroida) Unionoida).</p> <p>Conclusion</p> <p>The basal nature of the Unionoida within the autolamellibranch bivalves and the previously hypothesized single origin of DUI suggest that (1) DUI arose in the ancestral autolamellibranch bivalve lineage and was subsequently lost in multiple descendant lineages and (2) the mitochondrial genome characteristics observed in unionoid bivalves could more closely resemble the DUI ancestral condition. Descriptions and comparisons presented in this paper are fundamental to a more complete understanding regarding the origins and consequences of DUI.</p

Evidence for a Fourteenth mtDNA-Encoded Protein in the Female-Transmitted mtDNA of Marine Mussels (Bivalvia: Mytilidae)

BACKGROUND: A novel feature for animal mitochondrial genomes has been recently established: i.e., the presence of additional, lineage-specific, mtDNA-encoded proteins with functional significance. This feature has been observed in freshwater mussels with doubly uniparental inheritance of mtDNA (DUI). The latter unique system of mtDNA transmission, which also exists in some marine mussels and marine clams, is characterized by one mt genome inherited from the female parent (F mtDNA) and one mt genome inherited from the male parent (M mtDNA). In freshwater mussels, the novel mtDNA-encoded proteins have been shown to be mt genome-specific (i.e., one novel protein for F genomes and one novel protein for M genomes). It has been hypothesized that these novel, F- and M-specific, mtDNA-encoded proteins (and/or other F- and/or M-specific mtDNA sequences) could be responsible for the different modes of mtDNA transmission in bivalves but this remains to be demonstrated. METHODOLOGY/PRINCIPAL FINDINGS: We investigated all complete (or nearly complete) female- and male-transmitted marine mussel mtDNAs previously sequenced for the presence of ORFs that could have functional importance in these bivalves. Our results confirm the presence of a novel F genome-specific mt ORF, of significant length (>100aa) and located in the control region, that most likely has functional significance in marine mussels. The identification of this ORF in five Mytilus species suggests that it has been maintained in the mytilid lineage (subfamily Mytilinae) for ∼13 million years. Furthermore, this ORF likely has a homologue in the F mt genome of Musculista senhousia, a DUI-containing mytilid species in the subfamily Crenellinae. We present evidence supporting the functionality of this F-specific ORF at the transcriptional, amino acid and nucleotide levels. CONCLUSIONS/SIGNIFICANCE: Our results offer support for the hypothesis that "novel F genome-specific mitochondrial genes" are involved in key biological functions in bivalve species with DUI

A Synoptical Classification of the Bivalvia (Mollusca)

The following classification summarizes the suprageneric taxono-my of the Bivalvia for the upcoming revision of the Bivalvia volumes of the Treatise on Invertebrate Paleontology, Part N. The development of this classification began with Carter (1990a), Campbell, Hoeks-tra, and Carter (1995, 1998), Campbell (2000, 2003), and Carter, Campbell, and Campbell (2000, 2006), who, with assistance from the United States National Science Foundation, conducted large-scale morphological phylogenetic analyses of mostly Paleozoic bivalves, as well as molecular phylogenetic analyses of living bivalves. Dur-ing the past several years, their initial phylogenetic framework has been revised and greatly expanded through collaboration with many students of bivalve biology and paleontology, many of whom are coauthors. During this process, all available sources of phylogenetic information, including molecular, anatomical, shell morphological, shell microstructural, bio- and paleobiogeographic as well as strati-graphic, have been integrated into the classification. The more recent sources of phylogenetic information include, but are not limited to, Carter (1990a), Malchus (1990), J. Schneider (1995, 1998a, 1998b, 2002), T. Waller (1998), Hautmann (1999, 2001a, 2001b), Giribet and Wheeler (2002), Giribet and Distel (2003), Dreyer, Steiner, and Harper (2003), Matsumoto (2003), Harper, Dreyer, and Steiner (2006), Kappner and Bieler (2006), Mikkelsen and others (2006), Neulinger and others (2006), Taylor and Glover (2006), Kříž (2007), B. Morton (2007), Taylor, Williams, and Glover (2007), Taylor and others (2007), Giribet (2008), and Kirkendale (2009). This work has also benefited from the nomenclator of bivalve families by Bouchet and Rocroi (2010) and its accompanying classification by Bieler, Carter, and Coan (2010).This classification strives to indicate the most likely phylogenetic position for each taxon. Uncertainty is indicated by a question mark before the name of the taxon. Many of the higher taxa continue to undergo major taxonomic revision. This is especially true for the superfamilies Sphaerioidea and Veneroidea, and the orders Pectinida and Unionida. Because of this state of flux, some parts of the clas-sification represent a compromise between opposing points of view. Placement of the Trigonioidoidea is especially problematic. This Mesozoic superfamily has traditionally been placed in the order Unionida, as a possible derivative of the superfamily Unionoidea (see Cox, 1952; Sha, 1992, 1993; Gu, 1998; Guo, 1998; Bieler, Carter, & Coan, 2010). However, Chen Jin-hua (2009) summarized evi-dence that Trigonioidoidea was derived instead from the superfamily Trigonioidea. Arguments for these alternatives appear equally strong, so we presently list the Trigonioidoidea, with question, under both the Trigoniida and Unionida, with the contents of the superfamily indicated under the Trigoniida.Fil: Carter, Joseph G.. University of North Carolina; Estados UnidosFil: Altaba, Cristian R.. Universidad de las Islas Baleares; EspañaFil: Anderson, Laurie C.. South Dakota School of Mines and Technology; Estados UnidosFil: Araujo, Rafael. Consejo Superior de Investigaciones Cientificas. Museo Nacional de Ciencias Naturales; EspañaFil: Biakov, Alexander S.. Russian Academy of Sciences; RusiaFil: Bogan, Arthur E.. North Carolina State Museum of Natural Sciences; Estados UnidosFil: Campbell, David. Paleontological Research Institution; Estados UnidosFil: Campbell, Matthew. Charleston Southern University; Estados UnidosFil: Chen, Jin Hua. Chinese Academy of Sciences. Nanjing Institute of Geology and Palaeontology; República de ChinaFil: Cope, John C. W.. National Museum of Wales. Department of Geology; Reino UnidoFil: Delvene, Graciela. Instituto Geológico y Minero de España; EspañaFil: Dijkstra, Henk H.. Netherlands Centre for Biodiversity; Países BajosFil: Fang, Zong Jie. Chinese Academy of Sciences; República de ChinaFil: Gardner, Ronald N.. No especifica;Fil: Gavrilova, Vera A.. Russian Geological Research Institute; RusiaFil: Goncharova, Irina A.. Russian Academy of Sciences; RusiaFil: Harries, Peter J.. University of South Florida; Estados UnidosFil: Hartman, Joseph H.. University of North Dakota; Estados UnidosFil: Hautmann, Michael. Paläontologisches Institut und Museum; SuizaFil: Hoeh, Walter R.. Kent State University; Estados UnidosFil: Hylleberg, Jorgen. Institute of Biology; DinamarcaFil: Jiang, Bao Yu. Nanjing University; República de ChinaFil: Johnston, Paul. Mount Royal University; CanadáFil: Kirkendale, Lisa. University Of Wollongong; AustraliaFil: Kleemann, Karl. Universidad de Viena; AustriaFil: Koppka, Jens. Office de la Culture. Section d’Archéologie et Paléontologie; SuizaFil: Kříž, Jiří. Czech Geological Survey. Department of Sedimentary Formations. Lower Palaeozoic Section; República ChecaFil: Machado, Deusana. Universidade Federal do Rio de Janeiro; BrasilFil: Malchus, Nikolaus. Institut Català de Paleontologia; EspañaFil: Márquez Aliaga, Ana. Universidad de Valencia; EspañaFil: Masse, Jean Pierre. Universite de Provence; FranciaFil: McRoberts, Christopher A.. State University of New York at Cortland. Department of Geology; Estados UnidosFil: Middelfart, Peter U.. Australian Museum; AustraliaFil: Mitchell, Simon. The University of the West Indies at Mona; JamaicaFil: Nevesskaja, Lidiya A.. Russian Academy of Sciences; RusiaFil: Özer, Sacit. Dokuz Eylül University; TurquíaFil: Pojeta, John Jr.. National Museum of Natural History; Estados UnidosFil: Polubotko, Inga V.. Russian Geological Research Institute; RusiaFil: Pons, Jose Maria. Universitat Autònoma de Barcelona; EspañaFil: Popov, Sergey. Russian Academy of Sciences; RusiaFil: Sanchez, Teresa Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Sartori, André F.. Field Museum of National History; Estados UnidosFil: Scott, Robert W.. Precision Stratigraphy Associates; Estados UnidosFil: Sey, Irina I.. Russian Geological Research Institute; RusiaFil: Signorelli, Javier Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Silantiev, Vladimir V.. Kazan Federal University; RusiaFil: Skelton, Peter W.. Open University. Department of Earth and Environmental Sciences; Reino UnidoFil: Steuber, Thomas. The Petroleum Institute; Emiratos Arabes UnidosFil: Waterhouse, J. Bruce. No especifica;Fil: Wingard, G. Lynn. United States Geological Survey; Estados UnidosFil: Yancey, Thomas. Texas A&M University; Estados Unido

Eulimnadia graniticola

Eulimnadia graniticola species novae (Figure 1) Etymology: The name “ graniticola ” comes from the word “granite”, referring to the rock type that the type locality is situated in, and the Latin suffix “-cola”, which means “dweller”. Types: Holotype: female/ hermaphrodite, data: USA: Georgia: Dekalb County: Stone Mountain: rock outcrop depressional temporary wetland, ~ 500m elevation, 29 August 2005, T. Sanderson, R. Posgai and S. Weeks, deposited Los Angeles County Museum, LACM type number CR 2005 -038.1. Allotype: same data as holotype, deposited LACM CR 2005 -038.2. Paratypes: same data as holotype, 9 female /hermaphrodites, 3 males, deposited LACM CR 2005 -038.3. Paratypes: same data as holotype, 5 females / hermaphrodites, deposited D. C. Roger’s collections (DCR accession number 707). Additional Material Examined: USA: Florida: Monroe County: Upper Matecumbe Key, rainwater pool, 11 female / hermaphrodites, 17 April 2007, L. Hribar. Lower Matecumbe Key, rainwater pool, 1 female / hermaphrodite, 17 April 2007, L. Hribar. Windley Key, rainwater pool, 14 female / hermaphrodites, 1 male, 17 April 2007, L. Hribar. Vaca Key rainwater pool, 2 female / hermaphrodite, 31 October 2007, L. Hribar. All additional material deposited at Virginia Museum of Natural History. Description. Female: Head with ocular tubercle prominent, overreaching rostrum (Figure 1 A). Head broader than ocular tubercle. Contiguous compound eyes large, subcircular to reniform, 0.75 times the width of the ocular tubercle. Ocular angle smoothly arcuate to rostrum. Naupliar ocellus subtriangular, lying just posterior to, or slightly above and posterior to rostrum. Rostrum pronounced, broadly rounded to truncated, 0.5 to 0.3 times the width of the ocular tubercle (Figure 1 C, D). Ventral surface of rostrum even with ventral surface of head. Dorsal organ prominent, slightly pedunculate, directed anteriorly, hemispherical, with anterior face flat and circular. First antennae well below and posterior to rostrum, pedunculate, and 0.5 times as long as second antennal peduncle (Figure 1 A). Second antennae 2 to 2.5 times as long as head. Second antennal peduncle subequal in length to head, slightly geniculate, and bearing dorsal transverse rows of spiniform setae. Second antennal anterior flagellum (exopod) with six (right) or seven (left) annulations, each dorsally with a transverse row of spiniform setae. Posterior flagellum (endopod) with four (right) or five (left) such annulations, and about 0.17 times longer than anterior flagellum. Both flagellae with a ventral, longitudinal row of long plumose natatory setae, about 0.6 times the length of the peduncle. Carapace broadly oval, with three or four well separated, shallowly impressed, obscure growth lines, with the subapical growth line most salient (Figure 1 F). Adductor muscle scar broad, oblong, about twice as long as wide. Fourteen to sixteen pairs of thoracopods, with tenth and eleventh pairs bearing dorsally elongated flabellae for carrying the eggs (Figure 1 B). Telson with ten to thirteen pairs of posterior spines borne on the posteriolateral ridges (Figure 1 B). Caudal filaments originating on the posterior surface between the ridges at or about the fourth pair of spines. Telson posteriolateral ridges each terminating in an elongated spiniform projection, 2.5 to 3.0 times as long as the nearest spines. Cercopods projecting posteriorly from the ventral surface of the telson, each subtended by a anteriobasal spiniform projection, directed posteriolaterally over the base of the cercus. Cerci are subequal in length to the telson, and are margined medially with a longitudinal row of long plumose setae that extends from the base distally to the point where the cercus abruptly tapers to the apex. Male: Head as in female, except rostrum pronounced, truncated, 0.3 to 0.2 times the width of the ocular tubercle (Figure 1 E). Ventral surface of rostrum even with ventral surface of head. First antennae well below and posterior to rostrum, pedunculate, and subequal in length to second antennal peduncle. antennae approximately 2.5 times as long as head, and otherwise as in female. Carapace broadly oval (although maybe slightly acute anteriorly, Figure 1 G) and otherwise as in female. Sixteen pairs of thoracopods, with first and second pairs modified as claspers to amplex the female. First thoracopod (terminology follows McLaughlin, 1980) with endite I and II each bearing a longitudinal row of aciculate setae. Endite III without setae. All three endites slope out to the endite from the thoracopod, with an abrupt declivity distally. Endite IV broad, transverse, grasping surface with numerous flat topped denticles, and a distal fringe of spiniform setae. Endite IV with palp pedunculate, slightly longer than endite, and bearing a few short apical spiniform setae. Endite V broadly arcuate proximally, distal portion parallel to basal portion, grasping surface with numerous ventral flat topped denticles, and a subapical, suctorial organ on posterior side of endite apex. Endite VI elongate, slightly arcuate in proximal segment, and straight in distal segment. Proximal segment attaining the distal most portion of the arc of endite V, and bearing an anteriapical transverse row of spines. Endite VI distal segment apex broader than remainder of endite, and bearing several short aciculate setae apically, and three to five arcuate spines subapically posteriorly. Exopod filiform, not attaining endite IV. Epipod broadly ovate. Second thoracopod similar to first. Last seven to nine thoracic segments each with a dorsal transverse row of spines, directed posteriorly, and originating submarginaly. Thoracic segments and telson as in female. Egg: Subspherical, ~ 200 μm in diameter. Surface with numerous, narrow, rectilinear paired polygons, ~ 100 μm in length, ~ 10 μm wide, with truncated ends. Spaces between polygons produced as rounded ridges. Spines or other projections absent. Differential Diagnosis: Eulimnadia graniticola n. sp. is a typical member of the genus Eulimnadia as defined by Rogers, et al. (in review). Specifically it is a typical limnadiid clam shrimp, with the occipital notch and condyle absent; frontal organ present and pedunculate; first antennae not segmented; carapace with dorsal margin smooth, lacking carinae, with an arcuate hinge line, rarely sinuate, umbone absent; male first two thoracopods with endite five bearing an apical suctorial organ; telson with a posteriorly directed spiniform projection present on the ventroposterior angle, anteriad of the cercopod base; caudal filament borne on a projecting mound; eggs spherical to subspherical or cylindrical to cylindrical with one end larger than the other, with large rectilinear polygonal depressions separated by ridges, occasionally with lamellar or setaform spines at polygon ridge line confluences (Belk, 1989; Martin, 1989; Martin and Belk, 1989; Rogers et al., in review; Rabet, in press). Unfortunately due to the tremendous morphological plasticity in the genus Eulimnadia, an adequate differential diagnosis of the adults is not possible at this time. This inherit plasticity in the Spinicaudata has frustrated many workers (Straškraba 1966; Sissom 1971; Belk 1989; Martin and Belk 1989; Martin 1989), however a certain amount of morphological stability in the eggs has been shown to be useful in defining Eulimnadia species (Belk 1989; Martin and Belk 1989), or at least species groups (Brendonck et al. 1990). With this in mind, based on egg morphology, we can say that E. graniticola is most similar to E. follisimilis. Both species bear subspherical, spineless eggs, with linear, often paired, polygons, however the linear polygons in E. follisimilis are simple slits, whereas in E. graniticola the polygons are rectilinear, about one tenth as wide as long. All other American Eulimnadia species with subspherical eggs have subcircular, unpaired polygons (i.e.; E. brasiliensis, E. ovilunata, E. ovisimilis, E. diversa), or if paired rectilinear polygonal depressions are present, the eggs are much more angular, with the angles produced as spiniform structures (i.e.; E. astrova). Eulimnadia graniticola is separated from all other Eulimnadia species by the basic subspherical form of the egg. All remaining Eulimnadia species have a strongly angular, cylindrical or subcylindrical egg form (Belk, 1989; Martin, 1989; Martin and Belk, 1989; Rogers et al., in review; Rabet, in press). Reproduction: Among the 11 families that successfully hatched, both all “female” and mixed cohorts were noted (Table 1). Because these families were produced by isolated “females,” there was no possibility of male parentage, and thus these isolated “females” were either parthenogenetic females or self-compatible hermaphrodites. To distinguish between these alternatives, we examined the sex ratios among the families with males: these families produced an average of 18 % males and 82 % “females.” The sex-determining mechanism found in Eulimnadia texana predicts that selfing hermaphrodites that are “amphigenic” will produce 75 % hermaphrodites and 25 % males (Sassaman and Weeks 1993). The male-producing “females” in the current comparisons did not significantly deviate from this expectation (χ 2 (2) = 2.45; 0.3 <P <0.2), and thus we inferred that E. graniticola is androdioecious, with mixtures of males, monogenic (M) hermaphrodites and amphigenic (A) hermaphrodites (Table 1). Among the 11 isolated hermaphrodites, 4 (36 %) were found to be monogenic and 7 (64 %) were found to be amphigenic (Table 1).Published as part of Rogers, Christopher, Weeks, Stephen C. & Hoeh, Walter R., 2010, A new species of Eulimnadia (Crustacea; Branchiopoda; Diplostraca; Spinicaudata) from North America, pp. 61-68 in Zootaxa 2413 on pages 63-66, DOI: 10.5281/zenodo.19432

Data from: Widespread and persistent invasions of terrestrial habitats coincident with larval feeding behavior transitions during snail-killing fly evolution (Diptera: Sciomyzidae)

Background: Transitions in habitats and feeding behaviors were fundamental to the diversification of life on Earth. There is ongoing debate regarding the typical directionality of transitions between aquatic and terrestrial habitats and the mechanisms responsible for the preponderance of terrestrial to aquatic transitions. Snail-killing flies (Diptera: Sciomyzidae) represent an excellent model system to study such transitions because their larvae display a range of feeding behaviors, being predators, parasitoids or saprophages of a variety of mollusks in freshwater, shoreline and dry terrestrial habitats. The remarkable genus Tetanocera (Tetanocerini) occupies five larval feeding groups and all of the habitat types mentioned above. This study has four principal objectives: (i) construct a robust estimate of phylogeny for Tetanocera and Tetanocerini, (ii) estimate the evolutionary transitions in larval feeding behaviors and habitats, (iii) test the monophyly of feeding groups and (iv) identify mechanisms underlying sciomyzid habitat and feeding behavior evolution. Results: Bayesian inference and maximum likelihood analyses of molecular data provided strong support that the Sciomyzini, Tetanocerini and Tetanocera are monophyletic. However, the monophyly of many behavioral groupings was rejected via phylogenetic constraint analyses. We determined that (i) the ancestral sciomyzid lineage was terrestrial, (ii) there was a single terrestrial to aquatic habitat transition early in the evolution of the Tetanocerini and (iii) there were at least 10 independent aquatic to terrestrial habitat transitions and at least 15 feeding behavior transitions during tetanocerine phylogenesis. The ancestor of Tetanocera was aquatic with five lineages making independent transitions to terrestrial habitats and seven making independent transitions in feeding behaviors. Conclusions: The preponderance of aquatic to terrestrial transitions in sciomyzids goes against the trend generally observed across eukaryotes. Damp shoreline habitats are likely transitional where larvae can change habitat but still have similar prey available. Transitioning from aquatic to terrestrial habitats is likely easier than the reverse for sciomyzids because morphological characters associated with air-breathing while under the water's surface are lost rather than gained, and sciomyzids originated and diversified during a general drying period in Earth's history. Our results imply that any animal lineage having aquatic and terrestrial members, respiring the same way in both habitats and having the same type of food available in both habitats could show a similar pattern of multiple independent habitat transitions coincident with changes in behavioral and morphological traits