Worm Breeder's Gazette 7(2): 7
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In recent years there has been some pressure put on authors by one or two editors of journals to use the term 'juvenile' when describing the developmental stages of nematodes rather than the term 'larva'. The argument, I believe, goes something like this - In the Insecta the term larva is used to describe a particular stage totally unlike the adult in form which usually develops into an inert pupal stage which in turn metamorphoses into the adult, i.e. caterpillar pupa butterfly, etc. In exopterygote insects, in which the young stage hatches from the egg into a minute sexless and wingless replica of the adult, developmental stages are known as nymphs (not an appropriate term for nematodes as it refers to forms with wing buds). Those persons who insist that the term 'larvae' should not be applied to nematodes point out that these forms do not undergo a complex metamorphosis but usually develop stepwise through a series of moults into somewhat similar but larger shapes, and thus a term such as juvenile is more appropriate. I cannot find the term 'juvenile' in two biological dictionaries that I have consulted (Abercombie et al., 1973, Martin, 1976) Caveness (1964) in his 'Glossary of Nematological terms' defines juvenile as 'a fourth stage nematode which does not yet have functional gonads' or 'any immature nematode.' However, juvenile is an old word coming from the Latin word juvenis meaning a young person or in the Latin sense one in the prime of life (20th to 40th year - Cassell's Latin dictionary). One might say that scientists using the term 'juvenile' for nematodes could be accused of anthropomorphism, as all the definitions of juvenile or juvenility in the Shorter Oxford Dictionary (SOD) relate to persons. Furthermore, there is no indication that the term should imply no sexual capacity. The term 'larva' on the other hand is found in dictionaries of biology where it is defined as 'the immature form in which many animals exist after hatching from the egg and before undergoing metamorphosis to the adult form'. The word comes from the Latin larva meaning a ghost. The SOD defines it not only as 'an insect in the grub stage' but also as 'the immature form of other animals characterized by metamorphosis'. Metamorphosis is derived from a Greek word meaning 'to transform'. The SOD defines it in its physiological state as a 'change of form in animals and plants, or their parts, during life' so that whilst the term tends to be used in the Insecta it is not precluded from other forms of life such as the ammocoete larva of the lamprey or the various larval stages of nematodes for instance. I see no reason to forbid the use of the word 'juvenile' as used in nematology just as I see no reason for forbidding the use of the term 'larva.' These terms are now synonymous in nematology and whereas some may feel that juvenile is the more correct term others may feel, equally strongly, that the term 'larva' is more appropriate.