Journal Article

Comparative ultra-microscopy unraveling the regressive evolutionary signals: Insights from adaptations to extreme environment

Esmaeili, H.R., Echreshavi, S., Teimori, A. and Ahnelt, H.

Record Number:
6821
Year:
2025
Journal:
Zoologischer Anzeiger
Pages:
83-99
Volume:
314
Abstract:
Extreme environmental conditions have profound impacts on shaping the evolutionary trajectory of organisms. Cave-dwelling fishes, known as subterranean fishes, are notable examples of regressive evolution in response to the unique ecosystem of caves. Garra longipinnis (Teleostei: Cyprinidae: Labeoninae), a freshwater cyprinid endemic to the Arabian Peninsula, resides in both caves and surface habitats in northern Oman. It showcases two distinct morphotypes: the normal surface-dwelling form (epigean) with eyes and body pigmentation, and the blind cave-dwelling form (troglomorphic) lacking both eyes and pigmentation. Two morphotypes were analyzed comparatively, focusing on body scales using light and scanning electron microscopy to unravel the possible regressive evolutionary signals in cave-dwelling G. longipinnis, . The results revealed that the blind cave-dwelling form displayed a reduction in some scale features, including the reduction in scale size, smaller focal index, smaller extension index, and the absence of tubercles on the posterior portion of the scale. An additional change in the scales of the cave-dwelling population was related to the tubular part of the lateral line canal, which was longer with a wider opening (enhanced non-visual sensory systems). Furthermore, the cave population exhibited a relatively smaller body size than its surface-dwelling counterpart. These observed traits are regarded as adaptations to the constant darkness and poor nutrition conditions of the subterranean environments. By uncovering novel regressive evolutionary signals in scale morphology, this study contributes to our understanding of cave-dwelling inhabitants, shedding light on the independent influences of extreme environments on the evolution of fish populations and species.
Times Cited:
1
Related Records:
Reid, G. McG. (1978)
A sytematic study of labeine cyprinid fishes with particular reference to the comparative morphology, functional morphology and morphometrics of African Labeo species
Reid, G. McG. (1982)
The form, function and phylogenetic significance of the vomero-palatine organ in Cyprinid fishes
Sandford, M. (1983)
Ervaringen met enkele minder bekende holenvissen
Banister, K.E. (1984)
A subterranean population of Garra barreimiae (Teleostei, Cyprinidae) from Oman, with comments on the concept of regresive evolution
Waltham, A. C., Brown, R. D. and Middleton, T. C. (1985)
Karst and caves in the Jabal Akhdar, Oman
Fausel, P. (1990)
Das Sozialverhalten der Hohlenbarbe Garra barreimiae (Cyprinidae, Pisces)
Banister, K.E., Bell, J. and Crumpler, M. (1992)
Omani blind cave fish
Hanna, S.S. and Al-Belushi, M. (1996)
Introduction to the caves of Oman
Feulner, GR (1998)
Wadi fish of the UAE
Juberthie, C., Magniez, G., Decu, V. and Povara, I. (2001)
Oman
Timmermann, M., Schlupp, I. and Plath, M. (2004)
Shoaling behaviour in a surface-dwelling and cave-dwelling population of a barb Garra barreimiae (Cyprinidae: Teleostei)
Aden, E. (2004)
Ontogenetic eye regression in the cave fish Garra barreimiae
Kollmann, H., Sattmann, H. and Seeman, R. (2007)
"Al Hoota", ein karst- und hohlenkundlisches Forschungs- und Tourismusprojekt im Sultanat Oman
Timmermann, M and Plath, M (2009)
Phototactic response and light sensitivity in an epigean and a hypogean population of a barb (Garra barreimiae, Cyprinidae)
Colli, L., Paglianti, A., Berti, R., Gandolfi, G. and Tagliavini, J. (2009)
Molecular phylogeny of the blind cavefish Phreatichthys andruzzii and Garra barreimiae within the family Cyprinidae
Aden, E. (2010)
Eye development in the cave fish Garra barreimiae
Kruckenhauser, L., Haring, E., Seeman, R. and Sattmann, H. (2011)
Genetic differentiation between cave- and surface dwelling populations of Garra barreimiae (Cyprinidae) in Oman
Kirchner, S., Weimaier, T., Rattei, T., Sattmann, H. and Kruckenhauser, L. (2014)
Characterisation of 19 new microsatellite loci for the Omani barb Garra barreimiae from 454 sequences
Hamidan, N.A., Geiger, M.F. and Freyhof, J. (2014)
Garra jordanica, a new species from the Dead Sea basin with remarks on the relationship of G. ghorensis, G. tibanica and G. rufa (Teleostei: Cyprinidae)
Lujan, N.K. and Conway, K.W. (2015)
Life in the fast lane: A review of rheophily in freshwater fishes
Sayyadzadeh, G., Esmaeili, H.R. and Freyhof, J. (2015)
Garra mondica, a new species from the Mond River drainage with remarks on the genus Garra from the Persian Gulf basin in Iran
Freyhof, J., Hamidan, N.A., Feulner, G.R. and Harrison, I. (2015)
Chapter 3. The status and distribution of freshwater fishes of the Arabian Peninsula
García, N., Harrison, I., Cox, N. and Tognelli, M.F. (2015)
The status and distribution of freshwater biodiversity in the Arabian Peninsula.
Bagheri, M., Goudarzi, F., Zalaghi, A.H. and Savabieasfahani, M. (2016)
Habitat characteristics and population size of Iranocypris typhlops, the Iran cave barb
Esmaeili, H.R., Sayyadzadeh, G., Coad, B.W. and Eagderi, S. (2016)
Review of the genus Garra Hamilton, 1822 in Iran with description of a new species: a morpho-molecular approach (Teleostei: Cyprinidae)
Lyon, R.G., Geiger, M.F. and Freyhof, J. (2016)
Garra sindhi, a new species from the Jebel Samhan Nature Reserve in Oman (Teleostei: Cyprinidae).
Kirchner, S., Sattmann, H., Plan, L., Krenn, H., Victor, R., Haring, E. and Kruckenhauser, L. (2016)
As above, so below? Testing for gene flow between cave and surface-dwelling populations of Garra barreimiae
Kruckenhauser, L., Reginald, V. and Sattmann, H. (2016)
The fauna of the Al Hoota Cave in Northern Oman
Esmaeili, H.R., Mehraban, H., Abbasi, K., Keivany, Y. and Coad, B. (2017)
Review and updated checklist of freshwater fishes of Iran: Taxonomy, distribution and conservation status
Kirchner, S., Sattmann, H., Haring, E., Plan, L., Victor, R. and Kruckenhauser, L. (2017)
Investigating gene flow between the blind cavefish Garra barreimiae and its conspecific surface populations
Nebeshwar, K and Vishwanath, W (2017)
On the snout and oromandibular morphology of genus Garra, description of two new species from the Koladyne River basin in Mizoram, India, and redescription of G. manipurensis (Teleostei: Cyprinidae)
Pichler, A., Ahnelt, H., Kirchner, S., Sattmann, H., Haring, E., Handschuh, S., Freyhof, J., Victor, R. and Kruckenhauser, L. (2018)
The morphological diversity of Garra barreimiae [Teleostei: Cyprinidae]
Englmaier, G.K., Viñuela Rodríguez, N., Waidbacher, H., Palandacic, A., Tesfaye, G., Gessl, W. and Meulenbroek, P. (2020)
New data on Garra makiensis (Cyprinidae, Labeoinae) from the Awash River (Ethiopia) with remarks on its relationships to congeners on the Arabian Peninsula
Freyhof, J., Els, J., Feulner, G.R., Hamidan, N.A. and Krupp, F. (2020)
Freshwater fishes of the Arabian peninsula
Saemi-Komsari, M., Mousavi-Sabet, H., Sattari, M., Eagderi, S., Vatandoust, S. and Doadrio, I. (2020)
Descriptive osteology of Garra rossica (Nikolskii 1900)
Crawford, C.H., Randall, Z.S., Hart, P.B., Page, L.M., Chakrabarty, P., Suvarnaraksha, A. and Flammang, B.E. (2020)
Skeletal and muscular pelvic morphology of hillstream loaches (Cypriniformes: Balitoridae)
Kirchner, S., Kruckenhauser, L., Pichler. A., Borkenhagen, K. and Freyhof, J. (2020)
Revision of the Garra species of the Hajar Mountains in Oman and the United Arab Emirates with the description of two new species (Teleostei: Cyprinidae)
Zamani-Faradonbe, M., Keivany, Y., Dorafshan, S. and Zhang, E. (2021)
Two new species of Garra (Teleostei: Cyprinidae) from western Iran
Zamani-Faradonbe M. and Keivany Y. (2021)
Biodiversity and distribution of Garra species (Teleostei: Cyprinidae) in Iran
Zamani-Faradonbe, M. and Keivany, Y. (2021)
Comparative osteology of two Garra species (Cypriniformes, Cyprinidae) from Hormuz and Sistan basins of Iran
Zamani-Faradonbe, M., Zhang, E. and Keivany, Y. (2021)
Garra hormuzensis, a new species from the upper Kol River drainage in the Persian Gulf basin (Teleostei: Cyprinidae)
Kirchner, S., Sattmann, H., Haring, E., Victor, R. and Kruckenhauser, L. (2021)
Hidden diversity—Delimitation of cryptic species and phylogeography of the cyprinid Garra species complex in Northern Oman.
Sayyadzadeh, G., Al Jufaili, S.M. and Esmaeili, H.R. (2023)
Species diversity deflation: Insight into taxonomic validity of Garra species (Teleostei: Cyprinidae) from Dhofar Region in the Arabian Peninsula using an integrated morpho-molecular approach
Hashemzadeh Segherloo, I., Abdolahi‑Mousavi, S.E., Birgani, A.A., Normandeau, E., Hallerman, E., Bernatchez, L. and Freyhof, J. (2024)
Distribution and conservation of subterranean fishes of Iran: insights from a new locality
Esmaeili, H.R., Echreshavi, S., Teimori, A. and Ahnelt, H. (2025)
Comparative ultra-microscopy unraveling the regressive evolutionary signals: Insights from adaptations to extreme environment