Comparative anatomical study of internal brooding in three anascan bryozoans (Cheilostomata) and its taxonomic and evolutionary implications

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Comparative anatomical study of internal brooding in three anascan bryozoans (Cheilostomata) and its taxonomic and evolutionary implications. / Ostrovsky, Andrew N.; Grischenko, Andrei V.; Taylor, Paul D.; Bock, Phil; Mawatari, Shunsuke F.

In: Journal of Morphology, Vol. 267, No. 6, 06.2006, p. 739-749.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{40b7cad1e0ff49dcac4f63bcd49680c1,

title = "Comparative anatomical study of internal brooding in three anascan bryozoans (Cheilostomata) and its taxonomic and evolutionary implications",

abstract = "The anatomical structure of internal sacs for embryonic incubation was studied using SEM and light microscopy in three cheilostome bryozoans - Nematoflustra flagellata (Waters, 1904), Gontarella sp., and Biflustra perfragilis MacGillivray, 1881. In all these species the brood sac is located in the distal half of the maternal (egg-producing) autozooid, being a conspicuous invagination of the body wall. It consists of the main chamber and a passage (neck) to the outside that opens independently of the introvert. There are several groups of muscles attached to the thin walls of the brood sac and possibly expanding it during oviposition and larval release. Polypide recycling begins after oviposition in Gontarella sp., and the new polypide bud is formed by the beginning of incubation. Similarly, polypides in brooding zooids degenerate in N. flagellata and, sometimes, in B. perfragilis. In the evolution of brood chambers in the Cheilostomata, such internal sacs for embryonic incubation are considered a final step, being the result of immersion of the brooding cavity into the maternal zooid and reduction of the protecting fold (ooecium). Possible reasons for this transformation are discussed, and the hypothesis of Santagata and Banta (1996) that internal brooding evolved prior to incubation in ovicells is rejected.",

keywords = "Bryozoa, Cheilostomata, Evolution, Internal brood sacs, Ovicells, Parental care",

author = "Ostrovsky, {Andrew N.} and Grischenko, {Andrei V.} and Taylor, {Paul D.} and Phil Bock and Mawatari, {Shunsuke F.}",

year = "2006",

month = jun,

doi = "10.1002/jmor.10438",

language = "English",

volume = "267",

pages = "739--749",

journal = "Journal of Morphology",

issn = "0362-2525",

publisher = "Wiley-Blackwell",

number = "6",

}

RIS

TY - JOUR

T1 - Comparative anatomical study of internal brooding in three anascan bryozoans (Cheilostomata) and its taxonomic and evolutionary implications

AU - Ostrovsky, Andrew N.

AU - Grischenko, Andrei V.

AU - Taylor, Paul D.

AU - Bock, Phil

AU - Mawatari, Shunsuke F.

PY - 2006/6

Y1 - 2006/6

N2 - The anatomical structure of internal sacs for embryonic incubation was studied using SEM and light microscopy in three cheilostome bryozoans - Nematoflustra flagellata (Waters, 1904), Gontarella sp., and Biflustra perfragilis MacGillivray, 1881. In all these species the brood sac is located in the distal half of the maternal (egg-producing) autozooid, being a conspicuous invagination of the body wall. It consists of the main chamber and a passage (neck) to the outside that opens independently of the introvert. There are several groups of muscles attached to the thin walls of the brood sac and possibly expanding it during oviposition and larval release. Polypide recycling begins after oviposition in Gontarella sp., and the new polypide bud is formed by the beginning of incubation. Similarly, polypides in brooding zooids degenerate in N. flagellata and, sometimes, in B. perfragilis. In the evolution of brood chambers in the Cheilostomata, such internal sacs for embryonic incubation are considered a final step, being the result of immersion of the brooding cavity into the maternal zooid and reduction of the protecting fold (ooecium). Possible reasons for this transformation are discussed, and the hypothesis of Santagata and Banta (1996) that internal brooding evolved prior to incubation in ovicells is rejected.

AB - The anatomical structure of internal sacs for embryonic incubation was studied using SEM and light microscopy in three cheilostome bryozoans - Nematoflustra flagellata (Waters, 1904), Gontarella sp., and Biflustra perfragilis MacGillivray, 1881. In all these species the brood sac is located in the distal half of the maternal (egg-producing) autozooid, being a conspicuous invagination of the body wall. It consists of the main chamber and a passage (neck) to the outside that opens independently of the introvert. There are several groups of muscles attached to the thin walls of the brood sac and possibly expanding it during oviposition and larval release. Polypide recycling begins after oviposition in Gontarella sp., and the new polypide bud is formed by the beginning of incubation. Similarly, polypides in brooding zooids degenerate in N. flagellata and, sometimes, in B. perfragilis. In the evolution of brood chambers in the Cheilostomata, such internal sacs for embryonic incubation are considered a final step, being the result of immersion of the brooding cavity into the maternal zooid and reduction of the protecting fold (ooecium). Possible reasons for this transformation are discussed, and the hypothesis of Santagata and Banta (1996) that internal brooding evolved prior to incubation in ovicells is rejected.

KW - Bryozoa

KW - Cheilostomata

KW - Evolution

KW - Internal brood sacs

KW - Ovicells

KW - Parental care

UR - http://www.scopus.com/inward/record.url?scp=33646855261&partnerID=8YFLogxK

U2 - 10.1002/jmor.10438

DO - 10.1002/jmor.10438

M3 - Article

C2 - 16526057

VL - 267

SP - 739

EP - 749

JO - Journal of Morphology

JF - Journal of Morphology

SN - 0362-2525

IS - 6

ER -

ID: 5055252