Within Insects, only Endopterygotes show complete metamorphosis, including a distinct larval stage.^[10][11] Several classifications have been suggested by many entomologists,^[12][13] and following classification is based on Antonio Berlese classification in 1913. There are four main types of endopterygote larvae types:^[14][15]

1. 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
2. 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.
3. 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.
4. 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).

• 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

• 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.

• 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