Eutrigaster Cognetti de Martiis, 1904

Álvarez-Abreu, Oniel & Carrera-Martínez, Roberto, 2025, Annotated checklist of the earthworms (Annelida: Clitellata: Oligochaeta) from Hispaniola: a brief review and remarks, Zootaxa 5589 (1), pp. 346-362 : 350

publication ID

https://doi.org/10.11646/zootaxa.5589.1.27

publication LSID

lsid:zoobank.org:pub:17D73E5B-4212-404F-9522-4DE0F1D5B439

DOI

https://doi.org/10.5281/zenodo.14897140

persistent identifier

https://treatment.plazi.org/id/3235FE1A-DF3E-797D-B3EB-F8B0F6EE0D78

treatment provided by

Plazi (2025-02-19 22:57:11, last updated 2025-02-24 16:10:19)

scientific name

Eutrigaster Cognetti de Martiis, 1904
status

 

Genus Eutrigaster Cognetti de Martiis, 1904 View in CoL

Remarks. The genus Eutrigaster was erected to accommodate E. oraedivitis Cognetti de Martiis, 1904 based on the presence of three gizzards in an otherwise benhamiid earthworm. However, the structure that Cognetti de Martiis (1904) thought to be the first gizzard is in reality an enlarged semi-muscular proventriculus ( Sherlock et al. 2011). Sims (1987) expanded the genus to include Neotropical dichogasterid species without penial setae and later, Csuzdi & Zisci (1991) revised Eutrigaster and redefined it to species with a semi-muscular enlarged proventriculus in segment 5, and two gizzards in segments 6–7. Csuzdi & Zicsi (1991) divided the genus into two subgenera for species with ( Graffiona Csuzdi, 2014 ) or without penial setae ( Eutrigaster ). The classification suggested by Csuzdi & Zicsi (1991) transferred most Neotropical Dichogaster to Eutrigaster , with a few species still retaining their position within Dichogaster . Therefore, the only distinguishing characteristics between Eutrigaster and the predominantly African Dichogaster are that the latter lacks an enlarged proventriculus, and its gizzards are located in segments 5–6. However, several authors disagree with the validity of Eutrigaster as currently described (e.g., Fragoso & Reynolds 1997; James 1996, 2004; James & Gamiette, 2016). Firstly, the location of the gizzards is frequently variable in the literature and is very difficult to accurately determine as septae in this region are extremely thin and can break without leaving evident traces ( Fragoso & Reynolds 1997). Secondly, the degree of enlargement and musculature of the proventriculus seems to be a function of body size rather than evolutionary history ( James 1996). Interestingly, the Neotropical Dichogaster-Eutrigaster species seem to be unrelated to the Pantropical Dichogaster clades based on molecular phylogenetic inferences ( Anderson et al. 2017). Here, we keep the Hispaniolan native dichogasterid species in Eutrigaster for consistency purposes, but recognizing that a revision of this group is needed and that changes in the current classification of both Eutrigaster and Dichogaster and their subgenera are likely to occur through the application of phylogenetic and phylogenomic analyses.

Anderson, F. E., Williams, B. W., Horn, K. M., Erseus, C., Halanych, K. M., Santos, S. R. & James, S. W. (2017) Phylogenomic analyses of Crassiclitellata support major Northern and Southern Hemisphere clades and a Pangaean origin for earthworms. BMC Evolutionary Biology, 17, 1-18. https://doi.org/10.1186/s12862-017-0973-4

Cognetti de Martiis, L. (1904) Oligocheti di Costa Rica. Bollettino dei Musei di Zoologia ed Anatomia Comparata della Reale Universita di Torino, 19 (462), 1-11.

Csuzdi, Cs. & Zicsi, A. (1991) Uber die Verbreitung neuer und bekannter Dichogaster und Eutrigaster Arten aus Mittel- und Sudamerika (Oligochaeta: Octochaetidae). Regenwurmer aus Sudamerika 15. Acta Zoologica Hungarica, 37 (3 - 4), 177-192.

Csuzdi, Cs. (2014) Replacement names for Eutrigaster (Graffia) Csuzdi & Zicsi, 1991 and Dichogaster (Malawia) Csuzdi, 2010 (Oligochaeta, Acanthodrilidae). Zootaxa, 3811 (1), 149-150. https://doi.org/10.11646/zootaxa.3811.1.11

Fragoso, C. & Reynolds, J. W. (1997) On some earthworms from central and southeastern Mexican mountains, including two new species of the genus Dichogaster (Dichogastrini). Megadrilogica, 7, 9-19.

James, S. W. (1996) Nine new species of Dichogaster (Oligochaeta, Megascolecidae) from Guadeloupe (French West Indies). Zoologica Scripta, 25, 21-34. https://doi.org/10.1111/j.1463-6409.1996.tb00149.x

James, S. W. (2004) Earthworms from the eastern mountains of Jamaica: fourteen new species of Dichogaster (Oligochaeta, Megascolecidae). Organisms, Diversity and Evolution, 4, 277-294. https://doi.org/10.1016/j.ode.2004.04.003

James, S. W. & Gamiette, F. (2016) New species of Dichogaster Beddard, 1888 (Clitellata: Benhamiidae) with additional records of earthworms from Guadeloupe (French West Indies). Zootaxa, 4178 (3), 391-408. https://doi.org/10.11646/zootaxa.4178.3.5

Sherlock, E., Lee, S., Mcphee, S., Steer, M., Maes, J. M. & Csuzdi, C. (2011) The first earthworm collections from Nicaragua with description of two new species (Oligochaeta). Zootaxa, 2732 (1), 49-58. https://doi.org/10.11646/zootaxa.2732.1.4

Sims, R. W. (1987) New species and records of earthworms from Jamaica with notes on the genus Eutrigaster Cognetti, 1904 (Octochaetidae: Oligochaeta). Journal of Natural History, 21, 429-441. https://doi.org/10.1080/00222938700771101

Kingdom

Animalia

Phylum

Annelida

Class

Clitellata

SubClass

Oligochaeta

Order

Crassiclitellata

Family

Octochaetidae