Cannon, Lester R. G., Sewell, Kim B. (2001): Observations on Dactylocephala madagascariensis (Vay... more Cannon, Lester R. G., Sewell, Kim B. (2001): Observations on Dactylocephala madagascariensis (Vayssière, 1892), a temnocephalan with twelve tentacles from Madagascar. Zoosystema 23 (1): 11-17
Page 1. MARINE FLATWOR MS THE WORLD OF POLYCLADS k Leslie Newman and Lester Cannon . Page 2. Page... more Page 1. MARINE FLATWOR MS THE WORLD OF POLYCLADS k Leslie Newman and Lester Cannon . Page 2. Page 3. Page 4. Page 5. MARINE FLATWORMS THE WORLD OF POLYCLADS m . , Leslie Newman and Lester Cannon Page 6. Page 7. ...
Marine Flatworms provides a fascinating introduction to the intriguing world of polyclad flatworm... more Marine Flatworms provides a fascinating introduction to the intriguing world of polyclad flatworms, a group of large, free-living marine Platyhelminthes, which are found throughout the world but are most colourful in tropical waters. Although not related to molluscs, they are often mistaken for sea slugs because of their brilliant colour patterns. Written in an accessible style by two leading experts in the field, this book explores flatworms’ unusual structure, feeding habits, their curious reproductive behaviour (including ‘penis fencing’), their mimicry and toxicology. With a foreword by Professor Reinhardt Kristensen of the Copenhagen Zoological Museum, Marine Flatworms is the first comprehensive guide to polyclad families and genera. It contains more than 300 colour photographs from every part of the world.
A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in ... more A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in Brisbane, Queensland, Australia. Gieysztoria queenslandica n. sp. is a member of the Aequales group of Gieysztoria and differs from its congeners by possession of an S-shaped ovary, a Y-shaped oviduct leading to a separate receptaculum seminis, and the shape and size of the male copulatory organ. The sclerotic male organ of G. queenslandica is characterized by 27-32 broad, dagger-like spines arising from a hollow crescent-shaped girdle. The new species is seasonally abundant (AprilJuly) in an artificial lake present on the St. Lucia campus of the University of Queensland in Brisbane, Australia.
Two new genera and species of Rhabdocoela from a freshwater lake in Queensland, Australia are des... more Two new genera and species of Rhabdocoela from a freshwater lake in Queensland, Australia are described. Austrodalyellia ariena gen. nov. sp. nov. is a member of the Dalyelliidae Graff, 1905. The female system is typical of the family and includes paired finger-like vitellaria, a single ovary, bursa copulatrix and receptaculum seminis. The male system includes paired posterior testes and a copulatory organ with contained vesicula seminalis, vesicula granulorum and a complex stylet. Stylet structure is unique in the family and consists of five layered tines connected by a bifid base. The stylet appears to be derived from forms similar to those of Dalyellia and Microdalyellia. Haplodidymos rubroculatus gen. nov. sp. nov. is a member of the Typhloplanidae Graff, 1905 and characterized by a pair of large red eyes and posterior pharynx rosulatus. The female system includes paired vitellaria, a single ovary, bursa copulatrix, receptaculum seminis and uterus. The male system is characteriz...
Proceedings. Biological sciences / The Royal Society, May 25, 2016
Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephal... more Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephalan flatworms (Temnocephalida, Platyhelminthes) may have co-occurred and interacted through deep time, during a period of major environmental change. Therefore, reconstructing the history of their association is of evolutionary, ecological, and conservation significance. Here, time-calibrated Bayesian phylogenies of Euastacus species and their temnocephalans (Temnohaswellia and Temnosewellia) indicate near-synchronous diversifications from the Cretaceous. Statistically significant cophylogeny correlations between associated clades suggest linked evolutionary histories. However, there is a stronger signal of codivergence and greater host specificity in Temnosewellia, which co-occurs with Euastacus across its range. Phylogeography and analyses of evolutionary distinctiveness (ED) suggest that regional differences in the impact of climate warming and drying had major effects both on crayfish...
A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in ... more A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in Brisbane, Queensland, Australia. Gieysztoria queenslandica n. sp. is a member of the Aequales group of Gieysztoria and differs from its congeners by possession of an S-shaped ovary, a Y-shaped oviduct leading to a separate receptaculum seminis, and the shape and size of the male copulatory organ. The sclerotic male organ of G. queenslandica is characterized by 27-32 broad, dagger-like spines arising from a hollow crescent-shaped girdle. The new species is seasonally abundant (April-July) in an artificial lake present on the St. Lucia campus of the University of Queensland in Brisbane, Australia.
The state of knowledge of Australian fish parasitic ascardioids is briefly reviewed. The followin... more The state of knowledge of Australian fish parasitic ascardioids is briefly reviewed. The following species are described in full: Hysterothylacium cornutum, H. pelagicum, H. scomberoidei n. sp. Additional data are provided for Iheringascaris inquies. Maricostula n. gen. is established for those species that have lips with lateral flanges, deep postlabial grooves, interlabia, and elongate intestinal caecum, pyriform ventriculus, long sac-like
Eight new species belonging to the genus Cycloporus (Platyhelminthes. Polycladida, Euryleptidae) ... more Eight new species belonging to the genus Cycloporus (Platyhelminthes. Polycladida, Euryleptidae) are described from Australasian waters including eastern and western Australia and Papua New Guinea. The widely distributed species, Cycloporus variegatus is also redescribed and photographed for the first time. This study significantly increases the number of known Cycloporus species from 6 to 14 worldwide. Species are diagnosed primarily on
Temnocephalida includes species demonstrating many intermediate steps presenting the transition f... more Temnocephalida includes species demonstrating many intermediate steps presenting the transition from commensalism to parasitism. Dramatic morphological changes also occurred within this group but the number of supraspecific taxa is small, making the Temnocephalida an excellent model for evolutionary studies. Having summarised original and relevant published morphological data, we suggest a cladogram (phylogenetic tree) which nearly fully resolves the order of
A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in ... more A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in Brisbane, Queensland, Australia. Gieysztoria queenslandica n. sp. is a member of the Aequales group of Gieysztoria and differs from its congeners by possession of an S-shaped ovary, a Y-shaped oviduct leading to a separate receptaculum seminis, and the shape and size of the male copulatory organ.
Two pairs of identified sensory neurons innervating the sucker of Craspedella pedum (designated A... more Two pairs of identified sensory neurons innervating the sucker of Craspedella pedum (designated ADS1, ADS2) were found to accumulate DiO (3,3′dioctadecyloxacarbocyanine perchlorate) in vivo. The number, position and morphology of these neurons do not change throughout the postembryonic period of life. The axons of the ADS cells run forward within the ventral cords and their dendrites are parallel. They enter the sucker, ramify and terminate in numerous sensory endings in a wide peripheral zone of the disc. SEM reveals a single type of sensilla: small spot-like structures with several short cilia. They are scattered within the zone accommodating the openings of the adhesive glands and their distribution corresponds to that of the stained terminals. TEM observations (including about 20 full reconstructions from serial ultrathin sections) show five types of sensory endings on the disc with the following structures: (1) a short cilium and thin rootlet, (2) aciliary with a normal rootlet and a club-shaped apical portion, (3) aciliary with a club-shaped apical portion and a body similar to the apical part of the rootlet, (4) aciliary with large apical granule and (5) aciliary with small apical granules. Type 2-5 receptors form a morphological series suggesting that they are stages of formation of the common type 4 receptor. Not fully formed type 1 receptors have been found within the epidermis in adult animals. This suggests that, although ADS perikarya persist throughout the life of the animal, the nerve endings they form might be constantly renewed. Judging from the morphological and behavioural data, the functions of the ADS neurons might include: (1) monitoring of the close contact between the surface of the sucker and the sub-stratum prior to adhesion and (2) checking the viscosity of the adhesive secretion prior to release of the sucker.& b d y :
Archimonocelis medusa sp. nov. is described from eastern Australia. The species is characterized ... more Archimonocelis medusa sp. nov. is described from eastern Australia. The species is characterized by numerous (15-25) pharynges, as well as by details of sclerotized organs and karyotype. It is the first polypharyngeal marine flatworm known, and the first record of polypharyngy outside the Tricladida. Polypharyngy is interpreted as a disruption of the processes of pharyngeal induction and inhibition during development. Its possible adaptiveness is discussed.
... Lester R. G. Cannon, Australia 4006. ... 582 f 127 pm x 66 k 16 pm ; 441-806 pm X 50-96 pm) s... more ... Lester R. G. Cannon, Australia 4006. ... 582 f 127 pm x 66 k 16 pm ; 441-806 pm X 50-96 pm) surrounded by longitudinal muscles along its entire length, its lumen is open and filled with sperm anteriorly, but posteriorly lumen narrow, lined with foamy cells, walls become chitinous. ...
... Hickman (1955) considered three character-istics important-large testes, non-ciliated male an... more ... Hickman (1955) considered three character-istics important-large testes, non-ciliated male antrum and moderately short seminal vesicle-in ... seminal receptacle bears a resemblance to the free-living Provortex tubiferus Meixner, 1938 (Provorticidae) (see Luther 1948, p. 23). ...
Cannon, Lester R. G., Sewell, Kim B. (2001): Observations on Dactylocephala madagascariensis (Vay... more Cannon, Lester R. G., Sewell, Kim B. (2001): Observations on Dactylocephala madagascariensis (Vayssière, 1892), a temnocephalan with twelve tentacles from Madagascar. Zoosystema 23 (1): 11-17
Page 1. MARINE FLATWOR MS THE WORLD OF POLYCLADS k Leslie Newman and Lester Cannon . Page 2. Page... more Page 1. MARINE FLATWOR MS THE WORLD OF POLYCLADS k Leslie Newman and Lester Cannon . Page 2. Page 3. Page 4. Page 5. MARINE FLATWORMS THE WORLD OF POLYCLADS m . , Leslie Newman and Lester Cannon Page 6. Page 7. ...
Marine Flatworms provides a fascinating introduction to the intriguing world of polyclad flatworm... more Marine Flatworms provides a fascinating introduction to the intriguing world of polyclad flatworms, a group of large, free-living marine Platyhelminthes, which are found throughout the world but are most colourful in tropical waters. Although not related to molluscs, they are often mistaken for sea slugs because of their brilliant colour patterns. Written in an accessible style by two leading experts in the field, this book explores flatworms’ unusual structure, feeding habits, their curious reproductive behaviour (including ‘penis fencing’), their mimicry and toxicology. With a foreword by Professor Reinhardt Kristensen of the Copenhagen Zoological Museum, Marine Flatworms is the first comprehensive guide to polyclad families and genera. It contains more than 300 colour photographs from every part of the world.
A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in ... more A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in Brisbane, Queensland, Australia. Gieysztoria queenslandica n. sp. is a member of the Aequales group of Gieysztoria and differs from its congeners by possession of an S-shaped ovary, a Y-shaped oviduct leading to a separate receptaculum seminis, and the shape and size of the male copulatory organ. The sclerotic male organ of G. queenslandica is characterized by 27-32 broad, dagger-like spines arising from a hollow crescent-shaped girdle. The new species is seasonally abundant (AprilJuly) in an artificial lake present on the St. Lucia campus of the University of Queensland in Brisbane, Australia.
Two new genera and species of Rhabdocoela from a freshwater lake in Queensland, Australia are des... more Two new genera and species of Rhabdocoela from a freshwater lake in Queensland, Australia are described. Austrodalyellia ariena gen. nov. sp. nov. is a member of the Dalyelliidae Graff, 1905. The female system is typical of the family and includes paired finger-like vitellaria, a single ovary, bursa copulatrix and receptaculum seminis. The male system includes paired posterior testes and a copulatory organ with contained vesicula seminalis, vesicula granulorum and a complex stylet. Stylet structure is unique in the family and consists of five layered tines connected by a bifid base. The stylet appears to be derived from forms similar to those of Dalyellia and Microdalyellia. Haplodidymos rubroculatus gen. nov. sp. nov. is a member of the Typhloplanidae Graff, 1905 and characterized by a pair of large red eyes and posterior pharynx rosulatus. The female system includes paired vitellaria, a single ovary, bursa copulatrix, receptaculum seminis and uterus. The male system is characteriz...
Proceedings. Biological sciences / The Royal Society, May 25, 2016
Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephal... more Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephalan flatworms (Temnocephalida, Platyhelminthes) may have co-occurred and interacted through deep time, during a period of major environmental change. Therefore, reconstructing the history of their association is of evolutionary, ecological, and conservation significance. Here, time-calibrated Bayesian phylogenies of Euastacus species and their temnocephalans (Temnohaswellia and Temnosewellia) indicate near-synchronous diversifications from the Cretaceous. Statistically significant cophylogeny correlations between associated clades suggest linked evolutionary histories. However, there is a stronger signal of codivergence and greater host specificity in Temnosewellia, which co-occurs with Euastacus across its range. Phylogeography and analyses of evolutionary distinctiveness (ED) suggest that regional differences in the impact of climate warming and drying had major effects both on crayfish...
A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in ... more A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in Brisbane, Queensland, Australia. Gieysztoria queenslandica n. sp. is a member of the Aequales group of Gieysztoria and differs from its congeners by possession of an S-shaped ovary, a Y-shaped oviduct leading to a separate receptaculum seminis, and the shape and size of the male copulatory organ. The sclerotic male organ of G. queenslandica is characterized by 27-32 broad, dagger-like spines arising from a hollow crescent-shaped girdle. The new species is seasonally abundant (April-July) in an artificial lake present on the St. Lucia campus of the University of Queensland in Brisbane, Australia.
The state of knowledge of Australian fish parasitic ascardioids is briefly reviewed. The followin... more The state of knowledge of Australian fish parasitic ascardioids is briefly reviewed. The following species are described in full: Hysterothylacium cornutum, H. pelagicum, H. scomberoidei n. sp. Additional data are provided for Iheringascaris inquies. Maricostula n. gen. is established for those species that have lips with lateral flanges, deep postlabial grooves, interlabia, and elongate intestinal caecum, pyriform ventriculus, long sac-like
Eight new species belonging to the genus Cycloporus (Platyhelminthes. Polycladida, Euryleptidae) ... more Eight new species belonging to the genus Cycloporus (Platyhelminthes. Polycladida, Euryleptidae) are described from Australasian waters including eastern and western Australia and Papua New Guinea. The widely distributed species, Cycloporus variegatus is also redescribed and photographed for the first time. This study significantly increases the number of known Cycloporus species from 6 to 14 worldwide. Species are diagnosed primarily on
Temnocephalida includes species demonstrating many intermediate steps presenting the transition f... more Temnocephalida includes species demonstrating many intermediate steps presenting the transition from commensalism to parasitism. Dramatic morphological changes also occurred within this group but the number of supraspecific taxa is small, making the Temnocephalida an excellent model for evolutionary studies. Having summarised original and relevant published morphological data, we suggest a cladogram (phylogenetic tree) which nearly fully resolves the order of
A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in ... more A new species of Dalyelliidae, Gieysztoria queenslandica, is described from a freshwater lake in Brisbane, Queensland, Australia. Gieysztoria queenslandica n. sp. is a member of the Aequales group of Gieysztoria and differs from its congeners by possession of an S-shaped ovary, a Y-shaped oviduct leading to a separate receptaculum seminis, and the shape and size of the male copulatory organ.
Two pairs of identified sensory neurons innervating the sucker of Craspedella pedum (designated A... more Two pairs of identified sensory neurons innervating the sucker of Craspedella pedum (designated ADS1, ADS2) were found to accumulate DiO (3,3′dioctadecyloxacarbocyanine perchlorate) in vivo. The number, position and morphology of these neurons do not change throughout the postembryonic period of life. The axons of the ADS cells run forward within the ventral cords and their dendrites are parallel. They enter the sucker, ramify and terminate in numerous sensory endings in a wide peripheral zone of the disc. SEM reveals a single type of sensilla: small spot-like structures with several short cilia. They are scattered within the zone accommodating the openings of the adhesive glands and their distribution corresponds to that of the stained terminals. TEM observations (including about 20 full reconstructions from serial ultrathin sections) show five types of sensory endings on the disc with the following structures: (1) a short cilium and thin rootlet, (2) aciliary with a normal rootlet and a club-shaped apical portion, (3) aciliary with a club-shaped apical portion and a body similar to the apical part of the rootlet, (4) aciliary with large apical granule and (5) aciliary with small apical granules. Type 2-5 receptors form a morphological series suggesting that they are stages of formation of the common type 4 receptor. Not fully formed type 1 receptors have been found within the epidermis in adult animals. This suggests that, although ADS perikarya persist throughout the life of the animal, the nerve endings they form might be constantly renewed. Judging from the morphological and behavioural data, the functions of the ADS neurons might include: (1) monitoring of the close contact between the surface of the sucker and the sub-stratum prior to adhesion and (2) checking the viscosity of the adhesive secretion prior to release of the sucker.& b d y :
Archimonocelis medusa sp. nov. is described from eastern Australia. The species is characterized ... more Archimonocelis medusa sp. nov. is described from eastern Australia. The species is characterized by numerous (15-25) pharynges, as well as by details of sclerotized organs and karyotype. It is the first polypharyngeal marine flatworm known, and the first record of polypharyngy outside the Tricladida. Polypharyngy is interpreted as a disruption of the processes of pharyngeal induction and inhibition during development. Its possible adaptiveness is discussed.
... Lester R. G. Cannon, Australia 4006. ... 582 f 127 pm x 66 k 16 pm ; 441-806 pm X 50-96 pm) s... more ... Lester R. G. Cannon, Australia 4006. ... 582 f 127 pm x 66 k 16 pm ; 441-806 pm X 50-96 pm) surrounded by longitudinal muscles along its entire length, its lumen is open and filled with sperm anteriorly, but posteriorly lumen narrow, lined with foamy cells, walls become chitinous. ...
... Hickman (1955) considered three character-istics important-large testes, non-ciliated male an... more ... Hickman (1955) considered three character-istics important-large testes, non-ciliated male antrum and moderately short seminal vesicle-in ... seminal receptacle bears a resemblance to the free-living Provortex tubiferus Meixner, 1938 (Provorticidae) (see Luther 1948, p. 23). ...
Uploads
Papers by Lester Cannon