Brementia illgi Laubier and Lafargue, 1974

Boxshall, Geoff A. & Marchenkov, Andrey, 2007, A revision of the Brementia - group of genera (Copepoda: Notodelphyidae), with descriptions of a new genus and four new species, Zootaxa 1459, pp. 37-68 : 51-52

Brementia illgi Laubier and Lafargue, 1974

Material examined: none.

Differential Diagnosis: Body with indistinct segmentation. Cephalosome with narrow frontal margin bearing ventrally-directed rostrum. Rostrum forming simple lobe, without accessory median lobe. Post-rostral median lobe absent. Labrum a small lobe, partly concealed beneath rostrum. Lateral margin of cephalosome expanded ventrally to produce ridge-like swelling. Metasome with about 30% of length extending posterior to origin of leg 4: metasomal somites bearing legs near lateral margins. Mid-ventral processes present between legs 2, 3 and 4. Urosome vestigial, largely incorporated into metasomal trunk. Caudal rami lobate, fused to urosome at base, armed with setal remnants distally. Surface of body, rostrum, labrum, cephalosomic processes, and legs densely ornamented with surface setules.

Antennule unsegmented, lobate with broad base, tapering to setose apex. Antenna modified, with traces of segmentation; distal segment reflexed, bearing vestiges of sclerotised distal claw and other setal elements. Mandible represented by tapering lobate palp, lacking gnathobase. Tiny paired lobes located posterior to mandibles possibly representing maxillules. Maxillae and maxillipeds lacking. Legs 1–3 biramous, ventrolaterally-directed; each comprising elongate basal part (derived from protopod), carrying elongate, unsegmented but superficially annulate rami distally. Legs 1–3 each bearing small outgrowths ventrally on protopodal part. Leg 4 reduced, largely incorporated into body somite, weakly bilobed distally, with reduced lobes representing rami. Leg 5 not observed.

Body length of female approximately 2.60 mm. Male unknown.

Remarks: This species was described from Polysyncraton canetense by Laubier and Lafargue (1974), who commented on the numerous differences between this species and B. balneolensis , the type species of the genus. They refrained from establishing a new genus of accommodate this species because of the poor state of knowledge of the phylogeny of the “ophioseidimorph” Notodelphyidae . The phylogenetic analysis performed here ( Fig. 14 ) supports a monophyletic Brementia comprising both B. balneolensis and B. illgi .

Figures

FIGURE 14. Majority rule consensus tree showing estimated relationships between genera of Brementia - group with the family Notodelphyidae. The tree is the consensus of 10 equally parsimonious trees (branch length = 34). Values given above line are bootstrap values. Numbers below the line indicate the characters supporting the main clades. * Anoplodelphys incertae represents three taxa: A. incertae, A. galli and A. cf. galli, all of which have identical scores for the characters used in the analysis. Similarly, Achelidelphys chengae also represents Achelidelphys papuensis n. sp. which has identical scores for the characters used.