One‐Sided Ejaculation of Echidna Sperm Bundles

Johnston, Susan J; Smith, Brett; Pyne, Michael; Stenzel, Deborah; Holt, William V.

doi:10.1086/522847

Cited by 29 publications

(26 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Monotremata: In Tachyglossus aculeatus, the bifid penis is anatomically symmetric, but in erection, one half is retracted, making it functionally asymmetric (Johnston et al 2007) Marsupialia: Symmetric (Prasad 1974 (Prasad 1974) Phylum Chordata: Reptilia Squamata: all snakes have unequal hemipenes. In gartersnakes, Shine et al (2000) found that the right hemipenis was slightly wider than the left.…”

Section: Phylum Chordata: Mammaliamentioning

confidence: 99%

Something gone awry: unsolved mysteries in the evolution of asymmetric animal genitalia

Schilthuizen

2013

Animal Biol

View full text Add to dashboard Cite

show abstract

Section: Phylum Chordata: Mammaliamentioning

confidence: 99%

Something gone awry: unsolved mysteries in the evolution of asymmetric animal genitalia

Schilthuizen

2013

Animal Biol

View full text Add to dashboard Cite

show abstract

“…2002); rat (Immler et al, 2007); and echidna (Johnson et al, 2007)]. Spermatozoan conjunction is found also among invertebrate phyla, with most examples being listed in a paper by Ishijima et al (Ishijima et al, 1999).…”

Section: M Woolley and Othersmentioning

confidence: 99%

A study of synchronisation between the flagella of bull spermatozoa, with related observations

Woolley

Crockett

Groom

et al. 2009

Journal of Experimental Biology

113

View full text Add to dashboard Cite

SUMMARYFlagellar synchronisation has been observed between bull spermatozoa as they swam in a viscous medium, confined to a glass surface. This process is of interest in understanding the regulation of flagellar oscillation in general. Exact and persisting synchrony between bull spermatozoa occurred only when the spermatozoan heads were tightly coupled mechanically. For these cells, viscous coupling between the flagella was not by itself sufficient to establish synchronisation. Immediately on synchronisation, with the spermatozoan heads superposed, the paired spermatozoa showed rises in conjoint beat frequency, wave velocity and swimming velocity, i.e. in nearly all cases, the new conjoint values were greater than those shown by either of the two singleton spermatozoa. In our interpretation of these results, we put forward hydrodynamic arguments for seeing the primary change as a rise in wave velocity, via a decreased viscous resistance to bend propagation. Mechanistically, the rise in beat frequency is mysterious unless, as we suggest, it is consequential to the rise in wave velocity, and mediated by an as-yetunknown mechanical feedback process. The rise in swimming velocity is not surprising given the rise in wave velocity but there is evidence for an additional influence due to a subtle re-orientation of the conjoint spermatozoan heads, such that they experienced less frictional drag. Supplementary material available online at

show abstract

“…The sperm heads are thus considered rather fragile as there is no capacity for the formation of stable crosslinked nuclear protein-DNA complexes. Presumably platypus and echidna spermatozoa typically ascend the female tract as motile bundles (Johnston et al, 2007;Nixon et al, 2016), and although relatively little is known about fertilization mechanisms, it is interesting to see that the platypus genome encodes each of the four proteins of the human zona pellucida. Field and captive observations of echidna reproduction (Nicol and Andersen, 2007;Rismiller and McKelvey, 1996) have shown that the egg is incubated in the pouch for approximately 10 days after a pregnancy of about 3 weeks, whereupon the female eventually deposits the young in a nursery burrow.…”

Section: Monotremesmentioning

confidence: 99%

“…The echidna penis itself is most bizarre, being about a quarter of the animal's body length when erect and terminating in two sides, each side possessing a glans penis taking the form of 2 rosettes. The urethrae terminate on the surfaces of the rosette in a series of openings through which the semen emerges (Johnston et al, 2007); the platypus penis is equally bizarre and appears adapted for securing this organ into the urogenital sinus of the female during mating, which occurs in the water column.…”

Section: Monotremesmentioning

confidence: 99%

Mammalian Reproduction Overview

Holt

Johnston

2018

Encyclopedia of Reproduction

View full text Add to dashboard Cite

GlossaryAltricial Offspring that are hatched or born in a very immature and helpless condition so as to require parental care for some time. Delayed implantation Delayed implantation or embryonic diapause is a reproductive strategy used by approximately 100 different mammals in seven or eight different orders. In embryonic diapause, the embryo (blastocyst) does not immediately implant in the uterus after sexual reproduction has created the zygote, but is maintained in a state of dormancy. Eutheria Is the taxonomic name for the main group of living mammals. This taxon contains the placental mammals, of which humans are one species. Marsupials Mammals of an order whose members are born incompletely developed (i.e., altricial) and are typically carried and suckled in a pouch on the mother‫׳‬s belly. Marsupials are found chiefly in Australia and New Guinea, and also in America. Metatheria Is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. It is a slightly more inclusive group than the marsupials; it contains all of the living mammals with abdominal pouches (most female marsupials) as well as their more primitive ancestors and relatives. Monotreme Any member of the Monotremata, the most primitive order of mammals, characterized by certain birdlike and reptilian features, such as hatching young from eggs, and having a single opening for the digestive, urinary, and genital organs. Platypus and echidnas are the only extent monotremes. Phylogeny The evolutionary history of a group of organisms, especially as depicted in a family tree. Prototherian Primitive oviparous mammals belonging to the order Monotremata.

show abstract

One‐Sided Ejaculation of Echidna Sperm Bundles

Cited by 29 publications

References 4 publications

Something gone awry: unsolved mysteries in the evolution of asymmetric animal genitalia

Something gone awry: unsolved mysteries in the evolution of asymmetric animal genitalia

A study of synchronisation between the flagella of bull spermatozoa, with related observations

Mammalian Reproduction Overview

Contact Info

Product

Resources

About