The main difference between holotype and paratype is that a holotype is a single physical example of an organism used to describe a species, whereas a paratype is a specimen used to define an organism of a particular species, usually held in a museum or research collection.
Holotype and paratype are two specimens used to describe organisms in species. They are a type of biological sample.
Key Areas Covered
1. What is Holotype
– Definition, Facts, Importance
2. What is Paratype
– Definition, Facts, Importance
3. Similarities Between Holotype and Paratype
– Outline of Common Features
4. Difference Between Holotype and Paratype
– Comparison of Key Differences
What is Holotype
The holotype is an example of the organism used while describing the species. It can be a single physical example or one of the several examples. According to the International Code of Zoological Nomenclature (ICZN), it is one of the several name-bearing types. For example, Plebejus idas longinus contains one preserved specimen of that subspecies. Also, it can be held by a major museum, such as the Museum of Comparative Zoology at Harvard University. Importantly, the isotype in botany is a duplicate of the holotype, often two pieces of the same individual plant. Also, the haplotype should not be typical for a particular taxon, but ideally, it is.
Furthermore, just a fragment of an organism can also be a holotype in the case of a fossil. For example, a fossil leg stored at the Natural History Museum in London is a holotype of Pelorosaurus humerocristatus (Duriatitan), a large herbivorous dinosaur from the early Jurassic period. The specimen is not replaced when a better specimen is found. However, in the absence of the original holotype, the neotype is later appointed as the holotype. The lectotype can also become the holotype without the original specimen.
What is Paratype
The paratype is the specimen used to define a species, usually in museum research collections. Therefore, there can be more than one paratype. Importantly, it represents the species. The definition of the paratype relies on the definition of a type series. A type series is the material cited in the original publication. When the author describes ‘other materials described’, they belong to the paratypes. The author can also describe variations of the species. They belong to the species. However, some specimens can be dubiously included in the species. Therefore, when the type series contains five specimens, one becomes the holotype while the others become the paratypes.
Moreover, allotype is the related term to the paratype, indicating the opposite sex of the holotype. Therefore, it is also described in the first description. Also, allotype is a part of the type series. Thus, it is a paratype. Allotype is not functionally different from paratype. On the other hand, allotype does not have a nomenclature. Thus, it is not a name-bearing type and has no formal rules. Only the International Code of Zoological Nomenclature (ICZN) has a practice to designate it. However, it is difficult to designate the specimen when the allotype exhibits strong sexual dimorphism.
Similarities Between Holotype and Paratype
- Holotype and paratype are two specimen types of a species.
- They are important in describing a species.
Difference Between Holotype and Paratype
Holotype refers to a single type specimen upon which the description and name of a new species is based. In contrast, a specimen of an organism helps define what the scientific name of a species and another taxon represents.
The holotype is the specimen that serves as the nomenclature type, while the paratype represents the species.
The holotype is a single specimen clearly described in the original description, while the paratype belongs to the type series.
In brief, holotype and paratype are two specimens described by the author while describing a species. The holotype is the specimen in the original description of the species. Therefore, it is the nomenclature type. In comparison, paratype is the other specimens that are used to describe the species. Therefore, it also describes the species. Also, it belongs to the type series. Hence, the main difference between holotype and paratype is the presence in the original description.
- Type specimens: An overview. American Museum of Natural History. (n.d.). https://www.amnh.org/explore/news-blogs/from-the-collections-posts/just-our-types-a-short-guide-to-type-specimens#:~:text=Even%20when%20a%20holotype%20is,is%20ever%20lost%20or%20destroyed.