Family Isolaimiidae

                                 Revised 01/16/26

Classification:

                   Class Enoplea

          Subclass Dorylaimia

                     Order Isolaimiida

                  Suborder Isolaimiina

                 Superfamily Isolaimioidea

                Isolaimiidae Timm, 1969

Andrassy (2009) asserts that the root of Isolaimium is Isloaimi.  Consequently, the correct names of the Order, Sub-order, Superfamily and Family are, respectively, Isolaimiida, Isolaimiina. Isolaimioidea and Isolaimiidae and not Isolaimida, Isolaimina. Isolaimoidea and Isolaimidae as used by several authors.

Andrassy (2009) considered that, based on morphology and anatomy, the Isolaimidae may be closely related to the Merrmithidae.

A family of soil nematodes probably feeding on bacteria.

• long and very slender nematodes; 2-7 mm long

• cuticle may have punctations, most obvious on tail in longitudinal and transverse rows

• amphids apparently absent

• stoma very long, tubular, triradiate, thickened walls anteriorly

• females diovarial, amphidelphic, with ovaries sometimes reflexed

• male testes paired

• male spicules thick, gubemaculum small

• tails in both sexes short, conoid  to bluntly rounded with pointed tips

• large, paired caudal papillae on male tail; small paired papillae on female tail

• Mainly inhabitants of undisturbed sandy soils.

• Probably bacterial-feeding but may also be carnivores as bristles of oligochaetes reported in intestine of some specimens.

   Prior to 2018, only one genus.  Isolaimium, was in the family Isolaimiidae. However, per Abolafia and Pena-Santiago, 2018, the Aulolaimidae and its genera were transferred to the order Isolaimiida and family Isolaimiidae:

• There is a close relationship of Aulolaimus and Isolaimium in the order Isoaimiida. That order was shown with morphological and molecular analyses to be separate from other nematode orders.
• Consequently, the order Isolaimiida is considered valid and Aulolaimus and other genera belonging to the family Aulolaimidae were transferred to the Order Isolaimiida (Abolafia and Pena-Santiago, 2018).

    Go To Dictionary of Terminology 

References

Abolafia, J and Pena-Santiago, R. 2018. Morphology, taxonomy and phylogeny of the enigmatic genus Aulolaimus de Man, 1880 (Nematoda, Aulolaimidae). Zoologischer Anzeiger 277: 101-115.

Andrassy, I. 2009. Free-living Nematodes of Hungary (Nematoda Errantia) Vol. 111. Humgarian Natural History Museum, Budapest. 508p.

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