Apogastropoda

Apogastropoda
Various examples of Apogastropoda
Scientific classification
Kingdom:
Animalia
Phylum:
Mollusca
Class:
Gastropoda
Subclass:
Orthogastropoda
Infraclass:
Apogastropoda

Salvini-Plawen & Haszprunar, 1987[1]
Superorders

Heterobranchia
Caenogastropoda

Apogastropoda is a clade of gastropods uniting the highly diverse Caenogastropoda and Heterobranchia. Most caenogastropods are sea snails, whereas heterobranchs include not only sea snails but most species of sea slug, land snail, and land slug.

Taxonomy

Apogastropoda was coined by Salvini-Plawen and Hazprunar in 1987. In their original usage, it was intended as a paraphyletic grouping that contained caenogastropods and non-euthyneuran heterobranchs. In 1997, Ponder and Lindberg redefined the taxon to include Euthyneura, so that it would be monophyletic.

The monophyly of Apogastropoda is supported by both morphological[2] and molecular data.[3][4][5] Phylogenetic analyses based on the mitochondrial genome have historically found Apogastropoda to be non-monophyletic,[6] but this is considered an artifact of long branch attraction and the reliability of the mitochondrial genome for resolving deep relationships in molluscs has been questioned.[7] Early analyses of the mitogenome, which recovered Heterobranchia as the sister taxon of Patellogastropoda instead of Caenogastropoda, included data from only one patellogastropod taxon, Lottia digitalis, which has undergone a high rate of evolutionary change to its mitogenome that obscures its evolutionary relationships. Including mitochondrial genomes from more species of patellogastropod results in a monophyletic Apogastropoda being recovered, consistent with the results from other sources of data.[3]

Description

Apogastropods are generally characterized by a single pair of head tentacles, each of which contains a nerve that is deeply forked into two parallel branches. In euthyneurans, this condition is modified so that each nerve branch forms a separate tentacle.[8]

References

  1. ^ Salvini-Plawen, L. von; Haszprunar, G. (1987). "The Vetigastropoda and the systematics of streptonerous Gastropoda (Mollusca)". Journal of Zoology. 211 (4): 747–770 [762]. doi:10.1111/j.1469-7998.1987.tb04485.x.
  2. ^ Simone, Luiz Ricardo L. (2011). "Phylogeny of the Caenogastropoda (Mollusca), based on comparative morphology". Arquivos de Zoologia. 32 (4): 161–323. doi:10.11606/issn.2176-7793.v42i4p161-323. ISSN 0066-7870.
  3. ^ a b Uribe, Juan E.; Irisarri, Iker; Templado, José; Zardoya, Rafael (2018-12-17). "New patellogastropod mitogenomes help counteracting long-branch attraction in the deep phylogeny of gastropod mollusks". Molecular Phylogenetics and Evolution. 133: 12–23. doi:10.1016/j.ympev.2018.12.019. ISSN 1055-7903. PMID 30572020. S2CID 58579605.
  4. ^ Cunha, Tauana Junqueira; Giribet, Gonzalo (2019-03-13). "A congruent topology for deep gastropod relationships". Proceedings of the Royal Society B: Biological Sciences. 286 (1898): 20182776. doi:10.1098/rspb.2018.2776. ISSN 0962-8452. PMC 6458328. PMID 30862305.
  5. ^ Uribe, Juan E; González, Vanessa L; Irisarri, Iker; Kano, Yasunori; Herbert, David G; Strong, Ellen E; Harasewych, M G (2022-10-12). "A phylogenomic backbone for gastropod molluscs". Systematic Biology. 71 (6): 1271–1280. doi:10.1093/sysbio/syac045. eISSN 1076-836X. hdl:10261/279410. ISSN 1063-5157. PMID 35766870.
  6. ^ Cristina Grande, José Templado and Rafael Zardoya (2008). "Evolution of gastropod mitochondrial genome arrangements". BMC Evolutionary Biology. 8 (61): 61. Bibcode:2008BMCEE...8...61G. doi:10.1186/1471-2148-8-61. PMC 2291457. PMID 18302768.
  7. ^ Stöger, I.; Schrödl, M. (2012-12-08). "Mitogenomics does not resolve deep molluscan relationships (yet?)". Molecular Phylogenetics and Evolution. 69 (2): 376–392. doi:10.1016/j.ympev.2012.11.017. ISSN 1055-7903. PMID 23228545.
  8. ^ Brenzinger, Bastian; Schrödl, Michael; Kano, Yasunori (2021-10-25). "Origin and significance of two pairs of head tentacles in the radiation of euthyneuran sea slugs and land snails". Scientific Reports. 11 (1): 21016. Bibcode:2021NatSR..1121016B. doi:10.1038/s41598-021-99172-5. ISSN 2045-2322. PMC 8545979. PMID 34697382.
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