Pteropoda

Source: Wikipedia, the free encyclopedia.
Not to be confused with
Pteropodidae (megabats), or Pterosaur
(extinct flying reptiles).

Pteropoda
Temporal range: Campanian–Recent
A sea angel of the species Clione limacina
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Clade: Euopisthobranchia
Order: Pteropoda
Cuvier
(1804)

Pteropoda (

monophyletic.[2]

Pteropoda encompasses the two

parapodia) which protrude from their bodies) may reflect convergent adaptation
to their particular lifestyle.

Taxonomy

The group Pteropoda was established by

opisthobranch taxa (Phyllirhoë and Glaucus), the heteropoda taxa (Carinaria and Firola), and even the Ctenophora (Callianira
). In 1810, these authors divided the whole group in two separate groups: Those with a shell and those without a shell.

In 1824,

Nudibranchia
.

Other attempts were made to describe the Pteropoda:

Cuvier (and his followers) did not accept the classification by de Blainville; they preferred the original classification as described in Le Règne Animal
.

Rang (1829) followed the Cuvierian classification but tried to include the character of having a distinct head or not.[7] The German naturalist L. Oken went one step further and, for the sake of symmetry, wanted each order to contain four families and each family to contain four genera.[8][failed verification] P.A. 1829, divided the Pteropoda according to the size of their fins: "Macroptérygiens" (including only Pneumonoderma) and "Microptérygiens" (including all the others). W.B. Clark (1829) treated the Pteropoda as a family and emended the spelling to Pteropodidae (a name now re-used for a family of fruit bats)

Finally, all these attempts were abandoned and, as more and more species were described as a result of several scientific expeditions, the classification of the Pteropoda into Thecosomata and Gymnosomata was generally adopted.[a]

The relationship between these two clades is not unequivocally established, but it seems that they are sister taxa.[2]

Evolutionary history

Pteropods are estimated to have originated during the Early Cretaceous, around 133 million years ago, with the diversification into the major lineages occurring during the mid-late Cretaceous. The oldest known fossil pteropod is a member of Limacinidae from the early-middle Campanian deposits of the San Juan Islands.[9][10]

Phylogeny

Cladogram of genera and species of pteropods.
  Pteropoda  
  
Gymnosomata
  
         

  Clione antarctica

  Clione limacina

         

  Paedoclione doliiformis

         

  Pneumodermopsis spoeli

  
Thecosomata
  
  
Pseudothecosomata
  
         

  Cymbulia sibogae

  Peracle reticulata

  Euthecosomata  
  Limacinoidea  

  Heliconoides inflatus

  Limacinidae  
         
         

 

Limacina antarctica

  Limacina helicina

  Limacina retroversa

         

  Limacina lesueurii

         

  Limacina bulimoides

  Limacina trochiformis

  Cavolinioidea  
         

  Creseis acicula

  Creseis virgula

  Cavoliniidae  
         

  Styliola subula

         

  Hyalocylis striata

         

  Clio pyramidata

         

  Clio cuspidata

  Cuvierina atlantica

         
         

  Cavolinia inflexa

  Diacavolinia longirostris

         

  Diacria trispinosa

  Telodiacria danae

The phylogenetic tree has been inferred from 2,654 nuclear proteins (representing 834,394 concatenated amino acid positions).[11]

Threats

Vulnerability to ocean acidification

Unhealthy pteropod showing effects of ocean acidification
Main article: Ocean acidification

A study was conducted on the West Coast of the United States to see ocean acidification's effects on pteropods.[12] Limacina helicina was used to test the sensitivity to decreasing pH.[12] This species of pteropod is potentially vulnerable to the corrosive waters associated with ocean acidification due to their calcium carbonate shell.[13] The shell of a pteropod was immersed in ocean water with the projected pH level that the water will reach by the year 2100. After a month and a half in the water, the shell had almost completely dissolved.[12]

Distribution

Pteropods are found in all

Gymnosomata.[14]

Footnotes

  1. ^ Many of the new Pteropoda species were first described by French zoologists, for example, Jean René Constant Quoy and Joseph Paul Gaimard, Paul Rang, Alcide d'Orbigny, and Louis François Auguste Souleyet.

References

  1. doi:10.1007/s13127-013-0151-5
    .
  2. ^
    doi:10.1111/j.1439-0469.2006.00351.x
    .
  3. ^ "theco-". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  4. ^ Cuvier, G. (1804). "Mémoire sur l'Hyale et Ie Pneumoderme". Ann. Mus. Hist. Nat. Paris. 4: 232.
  5. ^ de Blainville, H.M.D. (1824). Diet. d. Sci. Nat (in French). Vol. xxxii. p. 271.
  6. ^ Gray, J.E. (1821). London Medical Repository. p. 235.
  7. ^ Rang, P. (1829). Manuel de l'histoire naturelle des mollusques et leurs coquilles [Handbook of the Natural History of Molluscs and their Shells] (in French).
  8. ^ Rang, S. (1825). "Description d'un genre nouveau de la classe des Ptéropodes" [Description of a new genera in the class Pteropoda]. Annales des Sciences Naturelles. 1 (in French). V: 284.
  9. PMID 32973093
    .
  10. ^ Janssen, A.W.; Goedert, J.L. (2016). "Notes on the systematics, morphology, and biostratigraphy of fossil holoplanktonic Mollusca, [part] 24. First observation of a genuinely Late Mesozoic thecosomatous pteropod". Basteria. 80: 59–63.
  11. PMID 32973093
    .
  12. ^
    PMID 24789895
    .
  13. ISSN 1726-4189
    .
  14. hdl:20.500.11850/60379
    . Retrieved 18 June 2018.

External links

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