Geminigera | Plagioselmis | Teleaulax

Introduction

• Geminigera described by Hill; type species Geminigera cryophila (marine; Hill 1991).
• Plagioselmis described by Butcher; invalid taxon, no type species designated (Butcher 1967).
• Teleaulax described by Hill; type species Teleaulax acuta (marine; Hill 1991)

Characteristics

• Nucleomorph free in periplastidial space or embedded in nucleus
• Type of biliprotein: PE545
• Probably dimorphic
• Light microscopy: red to bright brown cryptophytes, predominantly marine, one or two plastids each with a pyrenoid
• Ultrastructure of Geminigera: one deeply bi-lobed plastid with two pyrenoids, nucleomorph embedded in nucleus, sheet-like inner periplast, surface periplast component with fibrils and scales, combination of furrow and gullet, keeled rhizostyle.
• Ultrastructure of Plagioselmis: hexagonal plates (IPC), antapical tail without plates, furrow only (Novarino et al. 1994)
• Ultrastructure of Teleaulax: sheet-like inner periplast component, fibrillar surface periplast component, furrow only, keeled rhizostyle
• Marine or freshwater
  

Discussion of Phylogenetic Relationships

Similar to Cryptomonas and the Rhodomonas/Rhinomonas/Storeatula genus complex dimorphism seems to be present in this group (Figure 1; Deane et al. 2002).

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Figure 1. Molecular phylogeny of the Geminigera/Plagioselmis/Teleaulax genus complex. Maximum likelihood tree inferred from nuclear SSU rDNA sequences. Scale bar = substitutions per site. © 2008 Kerstin Hoef-Emden

References

Deane JA, Hill DRA, Brett SJ, McFadden GI (2002) Cryptomonad evolution: Nuclear 18S rDNA phylogeny versus cell morphology and pigmentation. J. Phycol. 38: 1236-1244

Butcher RW (1967) An Introductory Account of the Smaller Algae of British Coastal Waters. Part IV: Cryptophyceae. Fishery Investigations, Series IV. Ministry of Agriculture, Fisheries & Food, Her Majesty's Stationary Office, London

Hill DRA (1991a) A revised circumscription of Cryptomonas (Cryptophyceae) based on examination of Australian strains. Phycologia 30: 170-188

Novarino G, Lucas IAN, Morrall S (1994) Observations on the genus Plagioselmis (Cryptophyceae). Cryptogam. Algol. 15: 87-107

Shalchian-Tabrizi K, Bråte J, Logares R, Klaveness D, Berney C, Jakobsen KS (2008) Diversification of unicellular eukaryotes: cryptomonad colonizations of marine and fresh waters inferred from revised 18S rRNA phylogeny. Environ. Microbiol. 10: 2635-2644