Nebela Explained

Nebela is a diverse genus of testate amoebae of cosmopolitan distribution, belonging to the family Hyalospheniidae. They are "prey agglutinated" or "kleptosquamic" organisms, meaning they take the inorganic plates from their prey to construct their test.

Morphology

Members of this genus have a thin, transparent, pseudochitinous, flattened test that can be ovate, pyriform or elongate, with a length of around 180 microns. The surface of the test has numerous oval or circular scales of variable size, or in rare occasions rectangular or rod-like scales. The protoplasm is granular and colorless but can contain food vacuoles that show color. They have a single nucleus and a variable number of pseudopodia that are blunt in shape. The cell body is attached to the test's interior by strands of ectoplasm.

Classification

Nebela originally belonged to the family Nebelidae, but phylogenetic analyses showed that the genus was paraphyletic and the genera Hyalosphenia and Quadrulella, which belong to Hyalospheniidae, branch within Nebela. Accordingly, the family Nebelidae was synonymised with Hyalospheniidae.

Species

There are at least 13 remaining species in the genus:

• Nebela acolla
• Nebela aliciae
• Nebela barbata
• Nebela carinatella
• Nebela collaris (=Difflugia collaris ; =D. cancellata ; =D. reticulata ; =D. carpio ; =D. laxa ; =D. cellulifera ; =N. numata ; =N. bohemica ; =N. sphagnophila ; =N. tincta var. major ; =N. tincta f. stenostoma)
• Nebela cylindrica ^[1]
• Nebela equicalceus
• Nebela flabellulum
• Nebela guttata
• Nebela pechorensis
• Nebela rotunda
• Nebela tenella
• Nebela tincta (=Hyalosphenia tincta ; =N. bursella ; =N. parvula ; =N. minor)

Former species

The paraphyly of Nebela is slowly being resolved by transferring species from Nebela to other genera through phylogenetic analyses. The following species were previously considered Nebela but have been moved accordingly:

• Alabasta
  • Alabasta kivuense (=N. kivuense)
  • Alabasta longicollis (=N. longicollis)
  • Alabasta militaris (=N. militaris ; =N. bursella ; =N. americana var. bryophila)
• Cornutheca
  • Cornutheca ansata (=N. ansata)
  • Cornutheca saccifera (=N. saccifera)
  • Cornutheca hippocrepis (=N. hippocrepis)
  • Cornutheca jiuhuensis (=N. jiuhuensis)
• Gibbocarina
  • Gibbocarina galeata (=N. galeata)
  • Gibbocarina gracilis (=N. gracilis)
• Longinebela
  • Longinebela golemanskyi (=N. golemanskyi)
  • Longinebela meisterfeldi (=N. meisterfeldi)
  • Longinebela penardiana (=N. penardiana)
  • Longinebela speciosa (=N. speciosa)
  • Longinebela tubulosa (=N. tubulosa)
• Netzelia
  • Netzelia tuberculata (=N. tuberculata)
• Padaungiella
  • Padaungiella lageniformis (=N. lageniformis)
  • Padaungiella wailesi (=N. wailesi)
  • Padaungiella wetekampi (=N. wetekampi)
  • Padaungiella tubulata (=N. tubulata)
  • Padaungiella nebeloides (=N. nebeloides )
• Planocarina
  • Planocarina carinata (=N. carinata)
  • Planocarina marginata (=N. marginata)
  • Planocarina maxima (=N. maxima)
  • Planocarina spumosa (=N. spumosa)
• Physochila
  • Physochila griseola (=N. griseola)

Notes and References

1. Bonnet L . 1979 . Nouveaux thécamoebiens du sol X . Bulletin de la Société d'Histoire Naturelle de Toulouse . 115 . 106–118.