Chironomus sp. Nakuru

Wuelker, Wolfgang F., Kiknadze, I. I. & Istomina, A. G., 2011, Karyotypes of Chironomus Meigen (Diptera: Chironomidae) species from Africa, Comparative Cytogenetics 1, pp. 23-46 : 28

Chironomus sp. Nakuru

Previous report:

Wülker, 1980, banding pattern of arms A, E, and F. This species was not identified as well as Chironomus sp. Kisumu because there was no additional possibility to collect larvae for rearing. However, the study of Chironomus sp. Nakuru karyotype was very important for comparative analysis of Ethiopian Chironomus banding sequences with Chironomus sequences of the other continents.

Karyotype

(Fig. 3a). Haploid number n=4, arm combination AE CD BF G ( “pseudothummi” cytocomplex), centromeric bands not heterochromatinized, nucleoli on arms F and G, Balbiani rings on arms G, B, and A. Chromosomal polymorphism was not recorded.

Banding sequences (Fig 3b-f).

Arm A (Fig. 3b) has the banding sequence nakA1 identical with cosmopolitan basic sequence found in many species ( Chironomus holomelas , Chironomus melanescens , etc.)

Arm E (Fig. 3c) has banding sequence nakE1 differing by two inversion steps from the cosmopolitan basic sequence lonE1 ( Chironomus longistylus , Chironomus anthracinus etc.).

Arm C (Fig. 3e) has the sequence nakC1 differing by four inversion steps from basic pattern lonC1 ( Chironomus longistylus , Chironomus anthracinus , etc.) and by seven inversion steps from Chironomus piger ST (Fig. 7b).

Arm D (Fig. 3f) has the banding sequence nakD1 differing from pigST by three inversion steps.

Arm B (Fig. 3a) not mapped, monomorphic. The common BR is not developed.

Arm F (Fig. 3d) has the banding sequence nakF1 formed by four inversion steps from pigST.

The arm F of Chironomus sp. Nakuru has a nucleolus in region 17-19.

Arm G (Fig. 3a) has the banding sequence nakG1. It differs from the most of Chironomus species arm G by numerous Balbiani rings. It is possible to suggest that some of them can be nucleoli. But it is often impossible to differentiate nucleoli and Balbiani rings without electron microscopy or in situ hybridization.

In total, seven banding sequences are found in sequence pool of Chironomus sp. Nakuru, six chromosomal arms have Ethiopian endemic sequences, and one arm (A) a cosmopolitan basic sequence.

Larva:

long tubuli laterales at abdominal segment VII, extremely long antenna, gula light, no dark stripe on clypeus.

Distribution:

brook to SE of Lake Nakuru, Kenya