A larva (/ˈlɑːrvə/; pl.: larvae /ˈlɑːrviː/) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase of their life cycle.
A larva's appearance is generally very different from the adult form (e.g. caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. In the case of smaller primitive arachnids, the larval stage differs by having three instead of four pairs of legs.
Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population.
Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles, adults are immobile but their larvae are mobile, and use their mobile larval form to distribute themselves. These larvae used for dispersal are either planktotrophic (feeding) or lecithotrophic (non-feeding).
Some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species, the larvae are fed by female workers. In Ropalidia marginata (a paper wasp) the males are also capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae.
The larvae of some organisms (for example, some newts) can become pubescent and do not develop further into the adult form. This is a type of neoteny.
It is a misunderstanding that the larval form always reflects the group's evolutionary history. This could be the case, but often the larval stage has evolved secondarily, as in insects. In these cases[clarification needed], the larval form may differ more than the adult form from the group's common origins.
Selected types of larvae
| Animal | Name of larvae |
|---|---|
| Porifera (sponges) | coeloblastula (= blastula, amphiblastula), parenchymula (= parenchymella, stereogastrula) |
| Heterocyemida | Wagener's larva |
| Dicyemida | infusoriform larva |
| Cnidarians | planula (= stereogastrula), actinula |
| Ctenophora | cydippid larvae |
| Platyhelminthes | Turbellaria: Müller's larva, Götte's larva; Trematoda: miracidium, sporocyst, redia, cercaria; Monogenea: oncomiracidium; Cestoda: cysticercus, cysticercoid, oncosphere (or hexacanth), , plerocercoid |
| Annelida | nectochaete, polytroch |
| Nematoda | Dauer larva, microfilaria |
| Sipuncula | pelagosphera larva |
| Ectoprocta | cyphonautes, vesiculariform larvae |
| Nematomorpha | nematomorphan larva |
| Phoronids | actinotroch |
| Cycliophora | pandora, chordoid larva |
| Nemertea | pilidium, Iwata larva, Desor larva |
| Acanthocephala | acanthor |
| Locifera | Higgins larva |
| Brachiopoda | lobate larva |
| Priapula | loricate larva |
| Certain molluscs, annelids, nemerteans and sipunculids | trochophore |
| Certain molluscs | veliger |
| Mollusca: freshwater Bivalvia (mussels) | glochidium |
| Arthropoda: †Trilobita | protaspis (unjointed), meraspis (increasing number of joints, but 1 less than the holaspis), holaspis (=adult) |
| Arthropoda: Xiphosura | euproöps larva ("trilobite larva") |
| Arthropoda: Pycnogonida | protonymphon |
| Crustaceans | General: nauplius, metanauplius, protozoea, antizoea, pseudozoea, zoea, postlarva, cypris, primary larva, mysis Decapoda: zoea Rhizocephala: kentrogon |
| Insecta: Lepidoptera (butterflies and moths) | caterpillar |
| Insecta: Beetles | grub |
| Insecta: Flies, Bees, Wasps | maggot |
| Insecta: Mosquitoes | wriggler |
| Insecta: Orthoptera (crickets and grasshoppers), Odonata (dragonflies and damselflies), Hemiptera (true bugs) | nymph |
| Deuterostomes | dipleurula (hypothetical larva) |
| Echinodermata | bipinnaria, vitellaria, brachiollaria, pluteus, ophiopluteus, echinopluteus, auricularia |
| Hemichordata | tornaria |
| Urochordata | tadpole (does not feed, technically a "swimming embryo") |
| Fish (generally) | Ichthyoplankton |
| Fish: Petromyzontiformes (lamprey) | ammocoete |
| Fish: Anguilliformes (eels) | leptocephalus |
| Amphibians | tadpole, polliwog |
Insect larvae
Within Insects, only Endopterygotes show complete metamorphosis, including a distinct larval stage. Several classifications have been suggested by many entomologists, and following classification is based on Antonio Berlese classification in 1913. There are four main types of endopterygote larvae types:
- Apodous larvae – no legs at all and are poorly sclerotized. Based on sclerotization. All Apocrita are apodous. Three apodous forms are recognized.
- Eucephalous – with well sclerotized head capsule. Found in Nematocera, Buprestidae and Cerambycidae families.
- Hemicephalus – with a reduced head capsule, retractable in to the thorax. Found in Tipulidae and Brachycera families.
- Acephalus – without head capsule. Found in Cyclorrhapha
- Protopod larvae – larva have many different forms and often unlike a normal insect form. They hatch from eggs which contain very little yolk. E.g. first instar larvae of parasitic hymenoptera.
- Polypod larvae – also known as eruciform larvae, these larvae have abdominal prolegs, in addition to usual thoracic legs. They are poorly sclerotized and relatively inactive. They live in close contact with their food. Best example is caterpillars of lepidopterans.
- Oligopod larvae – have well-developed head capsule and mouthparts are similar to the adult, but without compound eyes. They have six legs. No abdominal prolegs. Two types can be seen:
- Campodeiform – well sclerotized, dorso-ventrally flattened body. Usually long legged predators with prognathous mouthparts. (lacewing, trichopterans, mayflies and some coleopterans).
- Scarabeiform – poorly sclerotized, flat thorax and abdomen. Usually short legged and inactive burrowing forms. (Scarabaeoidea and other coleopterans).
See also
- Crustacean larvae
- Ichthyoplankton
- Maggots
- Spawn (biology)
- Non-larval animal juvenile (immature) stages and other life cycle stages:
- In Porifera: olynthus, gemmule
- In Cnidaria: ephyra, scyphistoma, strobila, gonangium, hydranth, polyp, medusa
- In Mollusca: paralarva, young cephalopods
- In Platyhelminthes: hydatid cyst
- In Bryozoa: avicularium
- In Acanthocephala: cystacanth
- In Insecta:
- Nymphs and naiads, immature forms in hemimetabolous insects
- Subimago, a juvenile that resembles the adult in Ephemeroptera
- Instar, intermediate between each ecdysis
- Pupa and chrysalis, intermediate stages between larva and imago (the adult stage)
- Protozoan life cycle stages
- Apicomplexan life cycle
- Algal life cycle stages:
- Codiolum-phase
- Conchocelis-phase
- Marine larval ecology
References
- "TICK IDENTIFICATION". Division of environmental health. 4 October 2024.
- Qian, Pei-Yuan (1999), "Larval settlement of polychaetes", Reproductive Strategies and Developmental Patterns in Annelids, Dordrecht: Springer Netherlands, pp. 239–253, doi:10.1007/978-94-017-2887-4_14, ISBN 978-90-481-5340-4
- Chen, Zhang-Fan; Zhang, Huoming; Wang, Hao; Matsumura, Kiyotaka; Wong, Yue Him; Ravasi, Timothy; Qian, Pei-Yuan (2014-02-13). "Quantitative Proteomics Study of Larval Settlement in the Barnacle Balanus amphitrite". PLOS ONE. 9 (2): e88744. Bibcode:2014PLoSO...988744C. doi:10.1371/journal.pone.0088744. ISSN 1932-6203. PMC 3923807. PMID 24551147.
- Sen, R; Gadagkar, R (2006). "Males of the social wasp Ropalidia marginata can feed larvae, given an opportunity". Animal Behaviour. 71 (2): 345–350. doi:10.1016/j.anbehav.2005.04.022. S2CID 39848913.
- Wakahara, Masami (1996). "Heterochrony and Neotenic Salamanders: Possible Clues for Understanding the Animal Development and Evolution". Zoological Science. 13 (6): 765–776. doi:10.2108/zsj.13.765 (inactive 1 November 2024). ISSN 0289-0003. PMID 9107136. S2CID 35101681.
{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link) - Nagy, Lisa M.; Grbić, Miodrag (1999), "Cell Lineages in Larval Development and Evolutions of Holometabolous Insects", The Origin and Evolution of Larval Forms, Elsevier, pp. 275–300, doi:10.1016/b978-012730935-4/50010-9, ISBN 978-0-12-730935-4
- Raff, Rudolf A (2008-01-11). "Origins of the other metazoan body plans: the evolution of larval forms". Philosophical Transactions of the Royal Society B: Biological Sciences. 363 (1496): 1473–1479. doi:10.1098/rstb.2007.2237. ISSN 0962-8436. PMC 2614227. PMID 18192188.
- Williamson, Donald I. (2006). "Hybridization in the evolution of animal form and life-cycle". Zoological Journal of the Linnean Society. 148 (4): 585–602. doi:10.1111/j.1096-3642.2006.00236.x.
- Moore, R.C. (1959). Arthropoda I – Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Vol. Part O. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. O121, O122, O125. ISBN 978-0-8137-3015-8.
- "Division: Endopterygota – Amateur Entomologists' Society (AES)". www.amentsoc.org. Retrieved 2020-08-03.
- "Recognizing Insect Larval Types". University of Kentucky. Retrieved 28 April 2016.
- JOHNSON, NORMAN. TRIPLEHORN, CHARLES A. (2020). BORROR AND DELONG'S INTRODUCTION TO THE STUDY OF INSECTS. CENGAGE LEARNING CUSTOM P. ISBN 978-0-357-67127-6. OCLC 1163940863.
{{cite book}}: CS1 maint: multiple names: authors list (link) - Capinera, John L., ed. (2008). Encyclopedia of Entomology. Dordrecht: Springer Netherlands. doi:10.1007/978-1-4020-6359-6. ISBN 978-1-4020-6242-1.
- "Types of Insect Larva". Agri info. Archived from the original on 14 May 2016. Retrieved 28 April 2016.
- "Types of Insect Larva". agriinfo.in. 2017-03-23. Archived from the original on 2017-02-04. Retrieved 2021-11-22.
Bibliography
- Brusca, R. C. & Brusca, G. J. (2003). Invertebrates (2nd ed.). Sunderland, Mass. : Sinauer Associates.
- Hall, B. K. & Wake, M. H., eds. (1999). The Origin and Evolution of Larval Forms. San Diego: Academic Press.
- Leis, J. M. & Carson-Ewart, B. M., eds. (2000). The Larvae of Indo-Pacific Coastal Fishes. An Identification Guide to Marine Fish Larvae. Fauna Malesiana handbooks, vol. 2. Brill, Leiden.
- Minelli, A. (2009). The larva. In: Perspectives in Animal Phylogeny and Evolution. Oxford University Press. p. 160–170. link.
- Shanks, A. L. (2001). An Identification Guide to the Larval Marine Invertebrates of the Pacific Northwest. Oregon State University Press, Corvallis. 256 pp.
- Smith, D. & Johnson, K. B. (1977). A Guide to Marine Coastal Plankton and Marine Invertebrate Larvae. Kendall/Hunt Plublishing Company.
- Stanwell-Smith, D., Hood, A. & Peck, L. S. (1997). A field guide to the pelagic invertebrates larvae of the maritime Antarctic. British Antarctic Survey, Cambridge.
- Thyssen, P.J. (2010). Keys for Identification of Immature Insects Archived 2017-08-09 at the Wayback Machine. In: Amendt, J. et al. (ed.). Current Concepts in Forensic Entomology, chapter 2, pp. 25–42. Springer: Dordrecht.
External links
- Arenas-Mena, C. (2010) Indirect development, transdifferentiation and the macroregulatory evolution of metazoans. Philosophical Transactions of the Royal Society B: Biological Sciences. Feb 27, 2010 Vol.365 no.1540 653–669
A larva ˈ l ɑːr v e pl larvae ˈ l ɑːr v iː is a distinct juvenile form many animals undergo before metamorphosis into their next life stage Animals with indirect development such as insects some arachnids amphibians or cnidarians typically have a larval phase of their life cycle Larva of the Papilio xuthus butterflyEurosta solidaginis goldenrod gall fly larva A larva s appearance is generally very different from the adult form e g caterpillars and butterflies including different unique structures and organs that do not occur in the adult form Their diet may also be considerably different In the case of smaller primitive arachnids the larval stage differs by having three instead of four pairs of legs Larvae are frequently adapted to different environments than adults For example some larvae such as tadpoles live almost exclusively in aquatic environments but can live outside water as adult frogs By living in a distinct environment larvae may be given shelter from predators and reduce competition for resources with the adult population Animals in the larval stage will consume food to fuel their transition into the adult form In some organisms like polychaetes and barnacles adults are immobile but their larvae are mobile and use their mobile larval form to distribute themselves These larvae used for dispersal are either planktotrophic feeding or lecithotrophic non feeding Some larvae are dependent on adults to feed them In many eusocial Hymenoptera species the larvae are fed by female workers In Ropalidia marginata a paper wasp the males are also capable of feeding larvae but they are much less efficient spending more time and getting less food to the larvae The larvae of some organisms for example some newts can become pubescent and do not develop further into the adult form This is a type of neoteny It is a misunderstanding that the larval form always reflects the group s evolutionary history This could be the case but often the larval stage has evolved secondarily as in insects In these cases clarification needed the larval form may differ more than the adult form from the group s common origins Selected types of larvaeAnimal Name of larvaePorifera sponges coeloblastula blastula amphiblastula parenchymula parenchymella stereogastrula Heterocyemida Wagener s larvaDicyemida infusoriform larvaCnidarians planula stereogastrula actinulaCtenophora cydippid larvaePlatyhelminthes Turbellaria Muller s larva Gotte s larva Trematoda miracidium sporocyst redia cercaria Monogenea oncomiracidium Cestoda cysticercus cysticercoid oncosphere or hexacanth plerocercoidAnnelida nectochaete polytrochNematoda Dauer larva microfilariaSipuncula pelagosphera larvaEctoprocta cyphonautes vesiculariform larvaeNematomorpha nematomorphan larvaPhoronids actinotrochCycliophora pandora chordoid larvaNemertea pilidium Iwata larva Desor larvaAcanthocephala acanthorLocifera Higgins larvaBrachiopoda lobate larvaPriapula loricate larvaCertain molluscs annelids nemerteans and sipunculids trochophoreCertain molluscs veligerMollusca freshwater Bivalvia mussels glochidiumArthropoda Trilobita protaspis unjointed meraspis increasing number of joints but 1 less than the holaspis holaspis adult Arthropoda Xiphosura euproops larva trilobite larva Arthropoda Pycnogonida protonymphonCrustaceans General nauplius metanauplius protozoea antizoea pseudozoea zoea postlarva cypris primary larva mysis Decapoda zoea Rhizocephala kentrogonInsecta Lepidoptera butterflies and moths caterpillarInsecta Beetles grubInsecta Flies Bees Wasps maggotInsecta Mosquitoes wrigglerInsecta Orthoptera crickets and grasshoppers Odonata dragonflies and damselflies Hemiptera true bugs nymphDeuterostomes dipleurula hypothetical larva Echinodermata bipinnaria vitellaria brachiollaria pluteus ophiopluteus echinopluteus auriculariaHemichordata tornariaUrochordata tadpole does not feed technically a swimming embryo Fish generally IchthyoplanktonFish Petromyzontiformes lamprey ammocoeteFish Anguilliformes eels leptocephalusAmphibians tadpole polliwogInsect larvaeThe larvae of the Hercules beetle Dynastes hercules are among the largest of any species of insectCampodeiform larva of Micromus sp Within Insects only Endopterygotes show complete metamorphosis including a distinct larval stage Several classifications have been suggested by many entomologists and following classification is based on Antonio Berlese classification in 1913 There are four main types of endopterygote larvae types Apodous larvae no legs at all and are poorly sclerotized Based on sclerotization All Apocrita are apodous Three apodous forms are recognized Eucephalous with well sclerotized head capsule Found in Nematocera Buprestidae and Cerambycidae families Hemicephalus with a reduced head capsule retractable in to the thorax Found in Tipulidae and Brachycera families Acephalus without head capsule Found in Cyclorrhapha Protopod larvae larva have many different forms and often unlike a normal insect form They hatch from eggs which contain very little yolk E g first instar larvae of parasitic hymenoptera Polypod larvae also known as eruciform larvae these larvae have abdominal prolegs in addition to usual thoracic legs They are poorly sclerotized and relatively inactive They live in close contact with their food Best example is caterpillars of lepidopterans Oligopod larvae have well developed head capsule and mouthparts are similar to the adult but without compound eyes They have six legs No abdominal prolegs Two types can be seen Campodeiform well sclerotized dorso ventrally flattened body Usually long legged predators with prognathous mouthparts lacewing trichopterans mayflies and some coleopterans Scarabeiform poorly sclerotized flat thorax and abdomen Usually short legged and inactive burrowing forms Scarabaeoidea and other coleopterans See alsoCrustacean larvae Ichthyoplankton Maggots Spawn biology Non larval animal juvenile immature stages and other life cycle stages In Porifera olynthus gemmule In Cnidaria ephyra scyphistoma strobila gonangium hydranth polyp medusa In Mollusca paralarva young cephalopods In Platyhelminthes hydatid cyst In Bryozoa avicularium In Acanthocephala cystacanth In Insecta Nymphs and naiads immature forms in hemimetabolous insects Subimago a juvenile that resembles the adult in Ephemeroptera Instar intermediate between each ecdysis Pupa and chrysalis intermediate stages between larva and imago the adult stage Protozoan life cycle stages Apicomplexan life cycle Algal life cycle stages Codiolum phase Conchocelis phase Marine larval ecologyReferences TICK IDENTIFICATION Division of environmental health 4 October 2024 Qian Pei Yuan 1999 Larval settlement of polychaetes Reproductive Strategies and Developmental Patterns in Annelids Dordrecht Springer Netherlands pp 239 253 doi 10 1007 978 94 017 2887 4 14 ISBN 978 90 481 5340 4 Chen Zhang Fan Zhang Huoming Wang Hao Matsumura Kiyotaka Wong Yue Him Ravasi Timothy Qian Pei Yuan 2014 02 13 Quantitative Proteomics Study of Larval Settlement in the Barnacle Balanus amphitrite PLOS ONE 9 2 e88744 Bibcode 2014PLoSO 988744C doi 10 1371 journal pone 0088744 ISSN 1932 6203 PMC 3923807 PMID 24551147 Sen R Gadagkar R 2006 Males of the social wasp Ropalidia marginata can feed larvae given an opportunity Animal Behaviour 71 2 345 350 doi 10 1016 j anbehav 2005 04 022 S2CID 39848913 Wakahara Masami 1996 Heterochrony and Neotenic Salamanders Possible Clues for Understanding the Animal Development and Evolution Zoological Science 13 6 765 776 doi 10 2108 zsj 13 765 inactive 1 November 2024 ISSN 0289 0003 PMID 9107136 S2CID 35101681 a href wiki Template Cite journal title Template Cite journal cite journal a CS1 maint DOI inactive as of November 2024 link Nagy Lisa M Grbic Miodrag 1999 Cell Lineages in Larval Development and Evolutions of Holometabolous Insects The Origin and Evolution of Larval Forms Elsevier pp 275 300 doi 10 1016 b978 012730935 4 50010 9 ISBN 978 0 12 730935 4 Raff Rudolf A 2008 01 11 Origins of the other metazoan body plans the evolution of larval forms Philosophical Transactions of the Royal Society B Biological Sciences 363 1496 1473 1479 doi 10 1098 rstb 2007 2237 ISSN 0962 8436 PMC 2614227 PMID 18192188 Williamson Donald I 2006 Hybridization in the evolution of animal form and life cycle Zoological Journal of the Linnean Society 148 4 585 602 doi 10 1111 j 1096 3642 2006 00236 x Moore R C 1959 Arthropoda I Arthropoda General Features Proarthropoda Euarthropoda General Features Trilobitomorpha Treatise on Invertebrate Paleontology Vol Part O Boulder Colorado Lawrence Kansas Geological Society of America University of Kansas Press pp O121 O122 O125 ISBN 978 0 8137 3015 8 Division Endopterygota Amateur Entomologists Society AES www amentsoc org Retrieved 2020 08 03 Recognizing Insect Larval Types University of Kentucky Retrieved 28 April 2016 JOHNSON NORMAN TRIPLEHORN CHARLES A 2020 BORROR AND DELONG S INTRODUCTION TO THE STUDY OF INSECTS CENGAGE LEARNING CUSTOM P ISBN 978 0 357 67127 6 OCLC 1163940863 a href wiki Template Cite book title Template Cite book cite book a CS1 maint multiple names authors list link Capinera John L ed 2008 Encyclopedia of Entomology Dordrecht Springer Netherlands doi 10 1007 978 1 4020 6359 6 ISBN 978 1 4020 6242 1 Types of Insect Larva Agri info Archived from the original on 14 May 2016 Retrieved 28 April 2016 Types of Insect Larva agriinfo in 2017 03 23 Archived from the original on 2017 02 04 Retrieved 2021 11 22 BibliographyBrusca R C amp Brusca G J 2003 Invertebrates 2nd ed Sunderland Mass Sinauer Associates Hall B K amp Wake M H eds 1999 The Origin and Evolution of Larval Forms San Diego Academic Press Leis J M amp Carson Ewart B M eds 2000 The Larvae of Indo Pacific Coastal Fishes An Identification Guide to Marine Fish Larvae Fauna Malesiana handbooks vol 2 Brill Leiden Minelli A 2009 The larva In Perspectives in Animal Phylogeny and Evolution Oxford University Press p 160 170 link Shanks A L 2001 An Identification Guide to the Larval Marine Invertebrates of the Pacific Northwest Oregon State University Press Corvallis 256 pp Smith D amp Johnson K B 1977 A Guide to Marine Coastal Plankton and Marine Invertebrate Larvae Kendall Hunt Plublishing Company Stanwell Smith D Hood A amp Peck L S 1997 A field guide to the pelagic invertebrates larvae of the maritime Antarctic British Antarctic Survey Cambridge Thyssen P J 2010 Keys for Identification of Immature Insects Archived 2017 08 09 at the Wayback Machine In Amendt J et al ed Current Concepts in Forensic Entomology chapter 2 pp 25 42 Springer Dordrecht External linksWikisource has the text of the 1911 Encyclopaedia Britannica article Larval Forms Wikimedia Commons has media related to Larvae Look up larva in Wiktionary the free dictionary Arenas Mena C 2010 Indirect development transdifferentiation and the macroregulatory evolution of metazoans Philosophical Transactions of the Royal Society B Biological Sciences Feb 27 2010 Vol 365 no 1540 653 669
