Coleoidea#Paralarva

The earliest certain coleoids are known from the Mississippian sub-period of the Carboniferous Period, about 330 million years ago. Some older fossils have been described from the Devonian,

{{cite journal

|last1=Bandel |first1=Klaus

|last2=Reitner |first2=J.

|last3=Sturmer |first3=W.

|year=1983

|title=Coleoids from the Lower Devonian Black Slate ("Hunsruck-Schiefer")

|journal=Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen

|volume=165 |issue=3 |pages=397–417

|doi=10.1127/njgpa/165/1983/397

}}

but paleontologists disagree about whether they are coleoids.

{{Cite journal

|last1=Zuschin |first1=Martin

|year=2008

|title=Phylogeny and Evolution of the Mollusca

|journal=Marine Ecology

|volume=30 |issue=2 |page=269

|bibcode=2009MarEc..30..269Z

|doi=10.1111/j.1439-0485.2009.00287.x

}} Other cephalopods with internal shells, which could represent coleoids but may also denote the independent internalization of the shell, are known from the Silurian.

{{Cite journal

|last1=Turek |first1=V.

|last2=Manda |first2=Š.

|title=An endocochleate experiment in the Silurian straight-shelled cephalopod Sphooceras

|year=2012

|journal=Bulletin of Geosciences

|volume=87 |issue=4 |pages=767–813

|doi=10.3140/bull.geosci.1335 |doi-access=free

}} It has been hypothesized that the Early–Middle Cambrian fossil Nectocaris represents a coleoid (or other cephalopod) that lost its shell, possibly secondarily,

{{Cite journal

|last1=Smith |first1=M. R.

|last2=Caron |first2=J. B.

|title=Primitive soft-bodied cephalopods from the Cambrian

|year=2010

|journal=Nature

|volume=465 |issue=7297 |pages=469–472

|bibcode=2010Natur.465..469S

|doi=10.1038/nature09068

|hdl=1807/32368 |hdl-access=free

|pmid=20505727

|s2cid=4421029

}}

{{cite journal

|last1=Smith |first1=M. R.

|year=2013

|title=Nectocaridid ecology, diversity and affinity: early origin of a cephalopod-like body plan

|journal=Paleobiology

|volume=39 |issue=2 |pages=291–321

|doi=10.1666/12029

|bibcode=2013Pbio...39..297S

|s2cid=85744624

}} although it is more likely that Nectocaris represents an independent lineage within the Lophotrochozoa.{{Cite journal |last1=Kröger |first1=Björn |last2=Vinther |first2=Jakob |last3=Fuchs |first3=Dirk |date=August 2011 |title=Cephalopod origin and evolution: A congruent picture emerging from fossils, development and molecules: Extant cephalopods are younger than previously realised and were under major selection to become agile, shell-less predators |url=https://onlinelibrary.wiley.com/doi/10.1002/bies.201100001 |journal=BioEssays |language=en |volume=33 |issue=8 |pages=602–613 |doi=10.1002/bies.201100001|pmid=21681989 |s2cid=2767810 |url-access=subscription }}

By the Carboniferous, coleoids already had a diversity of forms, but the major radiation happened during the Tertiary.{{cite book | url=https://books.google.com/books?id=k3aBFSVUXqEC&dq=fossil+belemnites%2C+major+radiation+of+the+group+Tertiary&pg=PA42 | title=Cephalopods: Ecology and Fisheries | isbn=978-1-4051-4543-5 | last1=Boyle | first1=Peter | last2=Rodhouse | first2=Paul | date=15 April 2008 | publisher=John Wiley & Sons }} Although most of these groups are traditionally classified as belemnoids, the variation among them suggests that some are not closely related to belemnites.

{{Cite book

|last1=Doguzhaeva |first1=Larisa A.

|last2=Mapes |first2=Royal H.

|last3=Mutvei |first3=Harry

|year=2007

|chapter=A Late Carboniferous Coleoid Cephalopod from the Mazon Creek Lagerstätte (USA) with a radula, arm hooks, mantle tissues, and ink

|editor1-last=Landman |editor1-first=Neil H.

|editor2-last=Davis |editor2-first=Richard Arnold

|editor3-last=Mapes |editor3-first=Royal H.

|title=Cephalopods Present & Past: New Insights and Fresh Perspectives

|pages=121–143

|location=Berkeley & Los Angeles, California, USA

|publisher=University of California Press

}}

• Class Cephalopoda
• Subclass Nautiloidea: nautilus
• Subclass †Ammonoidea: ammonites
• Subclass Coleoidea
• Division †Belemnoidea: extinct belemnoids
• Genus †Jeletzkya
• Order †Hematitida
• Order †Phragmoteuthida
• Order †Donovaniconida
• Order †Aulacocerida
• Order †Belemnitida
• Division Neocoleoidea
• Superorder Decapodiformes
• Order Bathyteuthida
• Order †Belemnitida
• Order †Diplobelida
• Order Idiosepida
• Order Myopsida – coastal squid
• Order Oegopsida – neritic squid
• Order Sepiida – cuttlefish, pygmy, bobtail and bottletail squid
• Order Spirulida – ram's horn squid
• Superorder Octopodiformes
• Family †Trachyteuthididae (incertae sedis)
• Order Vampyromorphida: vampire squid
• Order Octopoda: octopus
• Superorder Palaeoteuthomorpha
• Order †Boletzkyida
• (uncertain order)
• family †Ostenoteuthidae

{{Cite journal

|last1=Garassino |first1=A.

|last2=Donovan |first2=D. T.

|year=2000

|title=A New Family of Coleoids from the Lower Jurassic of Osteno, Northern Italy

|journal=Palaeontology

|volume=43 |issue=6 |pages=1019

|doi=10.1111/1475-4983.00160 |doi-access=free

|bibcode=2000Palgy..43.1019G

}}

The majority of coleoid species are semelparous; dying after reproducing once, with males dying after insemination, and females dying after laying/brooding their clutch. A few species do not conform to this trend however; vampire squid, large Pacific striped octopus, and the West Atlantic scaled squid are thought to be iteroparous.{{cite journal |last1=Hoving |first1=Henk-Jan T. |last2=Laptikhovsky |first2=Vladimir V. |last3=Robison |first3=Bruce H. |title=Vampire squid reproductive strategy is unique among coleoid cephalopods |journal=Current Biology |date=20 April 2015 |volume=25 |issue=8 |pages=R322–R323 |url=http://oceanrep.geomar.de/28773/1/Hoving%2C%20Laptikhovsky%20and%20Robison%202015.pdf |access-date=29 July 2020 |doi=10.1016/j.cub.2015.02.018 |pmid=25898098 |s2cid=668950|doi-access=free |bibcode=2015CBio...25.R322H }}{{Cite journal|last1=Caldwell|first1=Roy L.|last2=Ross|first2=Richard|last3=Rodaniche|first3=Arcadio|last4=Huffard|first4=Christine L.|date=12 August 2015|title=Behavior and Body Patterns of the Larger Pacific Striped Octopus|journal=PLOS ONE|language=en|volume=10|issue=8|pages=e0134152|doi=10.1371/journal.pone.0134152|issn=1932-6203|pmc=4534201|pmid=26266543|bibcode=2015PLoSO..1034152C|doi-access=free}}{{cite journal |last1=Hoving |first1=H. J. T. |last2=Vecchione |first2=M. |title=Mating Behavior of a Deep-Sea Squid Revealed by in situ Videography and the Study of Archived Specimens |journal=The Biological Bulletin, University of Chicago |date=December 2012 |volume=223 |issue=3 |pages=263–267 |url=https://www.journals.uchicago.edu/doi/full/10.1086/BBLv223n3p263 |doi=10.1086/BBLv223n3p263 |pmid=23264472 |access-date=30 March 2025}} This is somewhat comparable to extant nautilus, which are also iteroparous, being long-lived animals.{{cite journal |author=Saunders WB |title=Nautilus Growth and Longevity: Evidence from Marked and Recaptured Animals |journal=Science |volume=224 |issue=4652 |pages=990–992 |date=June 1984 |pmid=17731999 |doi=10.1126/science.224.4652.990 |bibcode = 1984Sci...224..990S |s2cid=40891271 }}

Some authors prefer to separate coleoid reproduction using other terms:{{Cite journal | last1 = Rocha | first1 = F. | last2 = Guerra | first2 = Á. | last3 = González | first3 = Á. F. | doi = 10.1017/S1464793101005681 | title = A review of reproductive strategies in cephalopods | journal = Biological Reviews of the Cambridge Philosophical Society | volume = 76 | issue = 3 | pages = 291–304 | year = 2001 | pmid = 11569786| s2cid = 5777682 }}

1. One-time reproduction (formerly semelparity); being the occurrence of "simultaneous terminal spawning" (terminal: occurring at the end of life). This group is characterized by synchronous ovulation (the ova all ripen prior to spawning), single-cycle spawning, and the absence of growth between egg batches.

2. Multiple reproductive events (formerly iteroparity). This category is divided further into:

• (i) polycyclic spawning; where single egg batches/clutches develop and are laid multiple times during the spawning season, with growth occurring between production of egg batches and breeding seasons and the gonads regenerate/ripen between clutches, e.g. Nautilus ;

• (ii) multiple spawning; where multiple clutches of eggs develop simultaneously, which can be differentiated in the ovaries through their development stage (also known as group-synchronous ovulation). This method is defined by monocyclic spawning and the mother's growth between egg batches, e.g. Octopus chierchiae, Sthenoteuthis oualaniensis, Ommastrephes bartramii, and Dosidicus gigas ;

• (iii) intermittent terminal spawning; with group-synchronous ovulation, monocyclic spawning, but the mother does not somatically grow between egg batches, e.g. Loligo vulgaris subspp., Loligo bleekeri, Loligo forbesii, Illex coindetii, Todaropsis eblanae, Todarodes angolensis, and most populations of Sepia officinalis ;

• (iv) continuous spawning; where egg cells developed without any apparent "batches", with all stages of development potentially being present (or asynchronous ovulation), monocyclic spawning and growth between egg batches, e.g. Cirrothauma murrayi, Opisthoteuthis agassizii, Opisthoteuthis grimaldii and Grimpoteuthis glacialis, likely also includes Argonauta bottgeri, Argonauta hians, and Idiosepius pygmaeus.

Paralarvae ({{singular}}: paralarva) are young cephalopods immediately after hatching, prior to the development of adult diagnostic features and before exhibiting a similar ecology to older members of the same species. The term was introduced by Richard E. Young and Robert F. Harman in 1988; the term "larva" had been used previously, but it fell out of use as the term implied a metamorphosis occurred where larval body parts are lost completely and adult body parts developed from some "rudiments" left in an embryonic state; in contrast, young cephalopods do not undergo metamorphosis, they mostly grow morphometrically, though as this process still transforms the animal significantly, being comparable to the development of fish young (referred to as larva), the term "paralarva" (para: near, almost; near-larva/almost larva) was thus coined.{{cite journal|author=Richard Edward Young & Robert F. Harman|year=1988|title="Larva", "Paralarva", and "Subadult" in Cephalopod Terminology|journal=Malacologia|volume=29|issue=1|pages=201–207|url=https://www.biodiversitylibrary.org/page/25208582|access-date=August 13, 2011 }}{{cite web |last1=Young |first1=R. |last2=Harman |first2=R. |title="Larva,""paralarva" and "subadult" in cephalopod terminology |url=https://www.semanticscholar.org/paper/%22Larva,%22%22paralarva%22-and-%22subadult%22-in-cephalopod-Young-Harman/7919dede1370b30468c10c644ff7f6e052f2c0a6 |website=semanticscholar.org |s2cid=86032555 |access-date=6 April 2025}}{{cite book |last1=Zaragoza |first1=N. |last2=Quetglas |first2=A. |last3=Moreno |first3=A. |last4=Anderson |first4=Emory D. |title=Identification guide for cephalopod paralarvae from the Mediterranean Sea |publisher=ICES Cooperative Research Report |location=Copenhagen |date=2015 |volume=324 |url=https://digital.csic.es/bitstream/10261/323583/4/Zaragoza%20et%20al%202015b.pdf |isbn=978-87-7482-156-4 |issn=1017-6195|access-date=6 April 2025}}

Paralarvae have been observed only in members of the Octopoda and Teuthida (which constitutes the modern definition of Coleoidea).{{cite journal |last1=Fernández-Gago |first1=Raquel |last2=Molist |first2=Pilar |last3=Anadón |first3=Ramón |title=Tissues of Paralarvae and Juvenile Cephalopods |journal=Handbook of Diseases and Pathogens in Cephalopods |date=March 2019 |pages=87–109 |doi=10.1007/978-3-030-11330-8_5 |isbn=978-3-030-11329-2 |url=https://link.springer.com/chapter/10.1007/978-3-030-11330-8_5 |access-date=6 April 2025|url-access=subscription }} In the "iteroparous" species, the hatching of the paralarvae often heralds the death of the brooding mother. Paralarvae may be planktonic, or they may remain on the bottom (demersal zone). Planktonic paralarvae remain so for a time, feeding on small food items (such as detritus) until they start their transition into their adult habitat and niche;{{cite journal |last1=Fernández-Álvarez |first1=Fernando Á |last2=Machordom |first2=Annie |last3=García-Jiménez |first3=Ricardo |last4=Salinas-Zavala |first4=César A |last5=Villanueva |first5=Roger |title=Predatory flying squids are detritivores during their early planktonic life |journal=Sci Rep |date=February 21, 2018 |volume=8 |issue=1 |page=3440 |doi=10.1038/s41598-018-21501-y |pmid=29467371 |pmc=5821876 |bibcode=2018NatSR...8.3440F }} a young coleoid is termed a subadult when it displays the features diagnostic for species identification in the adult, without having to display size- or sex-specific features. An adult is thus an animal showing the diagnostic traits of its species, along with signs of sexual maturity.{{cite journal |last1=Vidal |first1=Erica A. G. |last2=Shea |first2=Elizabeth K. |title=Cephalopod ontogeny and life cycle patterns |journal=Frontiers in Marine Science |date=July 2023 |volume=10 |doi=10.3389/fmars.2023.1162735 |doi-access=free |bibcode=2023FrMaS..1062735V |url=https://www.researchgate.net/publication/372211459 |access-date=6 April 2025}}

File:Psychroteuthis glacialis paralarva2.jpg|Psychroteuthis glacialis

File:Taningia_persica.jpg|Taningia sp.

File:Fish3566 - Flickr - NOAA Photo Library.jpg|Octopus paralarva

File:Grimalditeuthis bonplandi paralarva (ROTATED).jpg|Grimalditeuthis bonplandi

Image:Chtenopteryx sicula paralarvae.jpg paralarvae. Left: Two very young paralarvae. The circular tentacular clubs bear approximately 20 irregularly arranged suckers. Two chromatophores are present on each side of the mantle. Centre: Ventral, dorsal and side views of a more advanced paralarva. An equatorial circulet of seven large yellow-brown chromatophores is present on the mantle. Posteriorly the expanded vanes of the gladius are visible in the dorsal view. Right: Ventral and dorsal views of a very advanced paralarva.]]

{{reflist}}

• {{CephBase Subclass |Coleoidea}}
• [http://tolweb.org/tree?group=Coleoidea Tree of Life web project: Coleoidea]
• [https://www.theatlantic.com/science/archive/2017/04/octopuses-do-something-really-strange-to-their-genes/522024/ "Octopuses Do Something Really Strange to Their Genes"]

{{Taxonbar |from=Q749814}}

Coleoidea

Category:Mollusc subclasses

Category:Carboniferous first appearances

Category:Neocephalopoda