تاکسونومی و بیوسیستماتیک (May 2022)
Identification Key for Entomobrya Rondani, 1861 (Collembola: Entomobryidae) Species in Iran
Abstract
AbstractCollembola or sprigtails are one of the most abundant terrestrial arthropods and are considered to be beneficial organisms that play an important role in the material cycle, including nitrogen and carbon, by feeding on decayed materials. The Entomobryidae family is characterized by features such as a longer fourth abdominal segment than other body segments, the presence of scales or a dense covering of ciliated macrosetae on the body, and the absence of a posterior antennal organ. The genus Entomobrya Rondani, 1861 is the most diverse genus that belongs to this family and the identification of its species is mainly based on the color pattern and chaetotaxy of the body. So far, 18 species of the genus have been reported in Iran. Due to the lack of identification key to species of this genus in Iran and the lack of access to resources, Iranian researchers are facing difficulties in studying the genus. In this study, the identification key of reported species of the genus Entomobrya in Iran is presented along with the image of the species.IntroductionCollembola are one of the most abundant terrestrial arthropods and due to the decomposition and decaying activity of many of them, they can be considered useful soil organisms. This class is divided into four orders including Entomobryomorpha, Poduromorpha, Symphypleona, and Neelipleona, and the Entomobryidae family is in the Entomobryomorpha group. The Entomobryidae family is one of the most diverse families, its members are known for their characteristics such as the fourth abdominal segment being long compared to the other segments of the body, the presence of scales or a dense covering of ciliated macroseatas on the body, and the absence of a post antennal organ. The Entomobryidae family is traditionally divided into two subfamilies: Entomobryinae and Orchesellinae. The genus Entomobrya Rondani, 1861 is one of the important genera of the Entomobryinae subfamily, which has the largest number of species reported in Iran compared to other genera. Identification of the species of this genus is mainly based on the color pattern and the chaetotaxy of the body. Materials and MethodsIn order to prepare the identification key of Entomobrya species, sources related to the reports of this genus from Iran including articles and theses were collected and a list of reported species of this genus in Iran was prepared. Then, the species identification key was adjusted based on the keys provided by Jordana (2012). Chaetotaxy of body bands is one of the important features in the identification of Entomobrya species. The chaetotaxy system used in this study is based on the chaetotaxy proposed by Jordana (2012). In the Entomobrini tribe, in addition to morphology and color pattern, the chaetotaxy of some body segments (head, second thoracic segment, and second-to-fourth abdominal segments) is important in identifying members of the tribe. Each of these clauses has regions with a specific chaetotaxy pattern. In the species identification key, the arrangement of the macroseatas for the dorsal parts of the head, the second thoracic segment, and the second-to-fourth abdominal segments are arranged. The total number, presence, or absence of macroseatas can be expressed with a simple chaetotaxy formula. Only the primary macrostases are included in this formula. FindingSo far, 18 species of this genus have been reported from Iran. Due to the lack of keys to identify the species of this genus in Iran and the lack of access to resources, Iranian researchers are facing difficulties in studying this genus. In the present study, the identification key of the reported species of Entomobrya genus in Iran is presented along with the image of the species. Conclusion and ResultsIdentification of Entomobrya species is one of the most challenging parts of the Entomobryidae family study. Because before this there was no identification key for the species of this genus in Iran. On the other hand, the great diversity of the body color pattern in the species of the genus sometimes causes confusion. Thus, some species such as E. schoetti species show a great variety in the color pattern. The different forms of this species range from completely white specimens without color patterns to dark specimens with pigment on all body parts. The key presented in this research is written based on the Palearctic species identification key prepared by Jordana (2012). This key includes the identification of different color forms of each species; this could help researchers not to consider them as separate species if they come across specimens with different color patterns from the same species.
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