Schineriella Murray & Fittkau

Description

Introduction

Medium-sized larvae, about 5.0 mm long. Head capsule slender, cephalic index about 0.5, posterior margin strongly but narrowly pigmented. Dorsally DP absent; S5 nearly directly mesial to S8 and both far posterior to S7. Ventrally S9, S10 and ventral pore (VP) almost equidistant in longitudinal linear series, S9, S10 and SSm not forming curved line, oval VP, bigger than setal sockets, opposite (lateral) to SSm.

Antenna

About 0.5 x as long as head, 4x as long as mandible. Antennal ratio 2.75. Basal segment about 12x as long as wide, with ring organ at 0.6; segment 2 about 14 x as long as wide, segment 3 about 2 x as long as wide, marginally shorter than last segment. Style slightly shorter than combined length of segments 3 plus 4. Peg sensilla about 0.65 x segment 3. Blade and accessory blade as long as flagellum.

Mandible

Moderately curved, gradually narrowed towards apex, about 2.5x as long as basal width. Apical tooth about 4x as long as basal width, 0.3x as long as mandible. Accessory tooth pointed, distal to mola, 0.5x as broad at base as base of molar. Mola dilate, very large, pointed, as broad at base as basal width of apical tooth. Seta subdentalis reaching 0.66x apical tooth length. Ventrolateral setae and ring organ aligned on outer margin of proximal half of mandible

Maxilla

Basal segment undivided, 3x as long as basal width, ring organ at 0.75

Body

Most posterior parapod claws simple-elongate, but (1)-2 bifid with inner spine half length of outer; others short and more robust.

Notes

Taxonomic Notes

Schineriella was erected for Tanypus schineri by Murray and Fittkau (1988) with descriptions and generic diagnoses for the adult male and pupal stages. The larva remains technically undescribed at this time, although known from a last instar tanypodine larva with the distinctive pre-pupal thoracic horn of Schineriella collected by P.M. Andreas Dettinger-Klemm, University of Marburg (via D. Murray) and also from associated larvae from the Netherlands (courtesy of Henk Vallenduuk and Henk Moller-Pillot). The larva closely resembles those of Paramerina (differing in the undivided maxillary palp) and Zavrelimyia. From the latter separation may be made by the granulose area of muscle attachment at the base of the ligula being narrow and nearly oval, in contrast to the broader band in Zavrelimyia that reaches the full basal width of the ligula. There may be difference in the ventral setal pattern which in Zavrelimyia S9, S10 and SSm form a near aligned or gently curved line, whereas in Schineriella this line is distinctly angled at S10 which lies posterior to S9.

Ecological Notes

Pupal and adult evidence pointed to larval occurrence in sediments of small, shallow nutrient-rich ponds and lakes with decaying leaf litter. The finding of a mature larva in storage ponds for motorway run-off water near Darmstadt-Dieburg (Hesse, Germany) tended to confirm eutrophy. Vallenduuk and Moller-Pillot (2008) report larvae regularly from mesotrophic ponds and lakes but although occurring also in eutrophic water bodies regard the species as intolerant of organic pollution.

S. schineri is known from Germany, Great Britain, the Netherlands and Turkey, but is likely to be wider distributed as larvae will have been confused with Zavrelimyia.

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