C. 'edwardi' Martin

  formerly Chironomus oppositus f. edwardi - Martin (2011)

Don Edward collected specimens of a species similar to C. oppositus from Lake Gwellup, near Perth, Western Australia. He obtained all life stages, but only provided larval specimens.  The species is therefore described on the basis of the larval morphology and cytology, which indicates that it is distinct from the species in the eastern states.

Larva:  medium sized melanotus-type larvae (female 15.0 mm (8); male 12.8 mm (6)), the lateral projections short (120-130 µm).  Ventral tubules in general about the same length (ant. 0.94-1.05; post. 0.99 - 1.07 mm) although on average the posterior pair are slightly longer.  Anal tubules about 300 µm, and about 4 times longer than wide.
Gular region slightly dark or dark over posterior half, some degree of darkening of the frontoclypeus.
Mentum (Fig. c) with 4th laterals slightly reduced (type I), c2 teeth relatively distinct, c1 relatively narrow and tall (type (III).
Ventromental plates (Fig. d) about 1.09-1.12x the mentum width and about 3.75-3.95x longer than deep; with smooth anterior edge, inner edges separated by about 0.30 (0.28-0.32) of the width of the mentum; 31-33 striae on each plate; VMR about 0.36 (0.29-0.42).
Pecten epipharyngis (Fig. a) with 11-17 teeth, which are sharp (type B) when not worn down and appear as type C.
Premandible (Fig. a) with the usual two teeth of about equal length, inner tooth less than twice the width of the outer (1.71).
Antenna (Fig. b) with basal segment about 4-4.1 times longer than wide; RO about a third to half way up from base of segment; AR about 2.1; ratio of segments (µm): 136 : 33 : 11: 14 : 7.
Distance between the antennal bases greater than that between the S4 setae, which are just near the beginning of the widening of the frontoclypeus.
Mandible (Fig. e) with third inner tooth almost separated and partly darkened(type IIB), with about 13-15 furrows on the outer surface near the base; about 11 taeniae in Pecten mandibularis.

Cytology:  4 polytene chromosomes with the pseudothummi arm combination AE, BF, CD, G.
Some patterns as in other forms of C. oppositus, but some differ.
Arm G with subterminal nucleolus and a relatively nearby BR.  No nucleolus in any other arm.
edwA1:    1a-e, 11 - 10, 2c - 1f, 3e - 2d, 8 - 9, 3f-i, 12c-a, 4 - 7, 13 - 19                            as oppA4
edwB1:    inversion of oppB2, puff (group 7) very near 4 distinctive bands (groups 24-26)
edwC1:    Typical groups, 3-4, about one third from distal end                                            as oppC1
edwD1:    1 - 2, 16 - 10d, 3a-d, 9 - 3e, 10a-c, 17 - 24                                                            as ausD1
edwE1:    1 - 3e, 10b - 3f, 10c - 13                                                                                      as halophilus, oppE1, etc.
edwF1:    1 - 2a, 10 - 2b, 11 - 23                                                                                          as oppF1 (without NOR)
edwG1:    subterminal nucleolus and nearby BR                                                                 possibly as oppG3

The obvious cytological differences from the C. oppositus forms of the Eastern states are the position of the puff in Arm B, and the absence of a nucleolus near the centromere of arm F.

Molecular datamtCOI: Partial BARCODE sequence is available and differs from that of other members of the C. oppositus group.

Types: Holotype: Salivary gland chromosome squash sl. 5?

Found:
Western Australia - Lake Gwellup, Perth