Phaenocora clavigera Hofsten, 1907

Houben, Albrecht M., Steenkiste, Niels Van & Artois, Tom J., 2014, Revision of Phaenocora Ehrenberg, 1836 (Rhabditophora, Typhloplanidae, Phaenocorinae) with the description of two new species, Zootaxa 3889 (3), pp. 301-354 : 334

Phaenocora clavigera Hofsten, 1907

(Figs 14C1–C2)

Derostoma coecum partim Fuhrmann 1894 only Fig. 53 with certainty.

Phaenocora clavigera Hofsten 1907: 550 –551, table 15 Fig. 17–18; Hofsten 1911: 3, 8, 10, 32, 37–46, TextFigs 9–10, plate 2 Figs 1–3 , 5–6 ; Hofsten 1912: 551, 557, 564, 582, 628, 678; Meixner 1915: 536; Luther 1921: 18, 29, 36, 38; Beklemischev 1929: 536, 551; Graff 1913: 134, 142–145, Figs 135, 145, 146; Gilbert 1935: 284, 293–294, 296, 299–300, 318, 327, 329, 341, 346–347, 355, 359, 363, 364, TextFigs 3Ka, 3Kb, table 1, 2; Beauchamp 1936: 149; Gilbert 1937: 67; Weise 1942: 145; Marcus 1946: 72, 81, 166; Luther 1963: 133; Kolasa 1973: 238, 241, 244, Figs 11A, B, C, 13; Müller & Faubel 1993: table 1.

Phoenocora clavigera (incorrect subsequent spelling) Cognetti de Martiis 1916: 193, 224, 227.

Phaenocora coecum (= P. clavigera ) Gilbert 1935: 329.

Phaenocora stagnalis (= P. clavigera ) Gilbert 1935: 293, 300, 327.

Phaenocora typhlops subsalina Luther 1921: 4 , 29, 31–38, TextFigs 15–23, plate 1 Fig. 13; Gilbert 1935: 285, 302, 304, 314, 341–342, 348, 365, table 1, 2; Marcus 1946: 72.

Phaenocora subsalina Beklemischev 1929: 551 ; Luther 1963: 127, 132, Fig. 44; Karling 1974: 50, 64, 80, Figs 109–111, table 1; Ax 2008: 411, Fig. 192D–F.

Known distribution: Münchenstein near Basel ( Switzerland) ( Fuhrmann 1894); lake Brienz near Kienholz ( Switzerland) in mud from the bottom ( Hofsten 1907); lake Brienz and lake Geneva ( Switzerland) and Denmark? (see Hofsten 1912 for localities and references; Graff 1913); vicinity of Berlin ( Germany) ( Weise 1942); in the vicinity of Hamburg ( Germany); along the Elbe estuary (see Müller & Faubel 1993 for localities and references). Bay belonging to the island Brännskär, Zoological Station Tvärminne ( Finland) ( Luther 1921), Thuringia ( Germany) in saline waters (see Ax 2008 for references).

Material examined: None.

Diagnosis: Animals up to 3.5 mm long. Visible eyes absent. Zoochlorellae not mentioned in literature. Amount of body pigmentation variable, sometimes absent. If present situated anteriorly to the pharynx and often as three longitudinal stripes. Male copulatory organ of the duplex-type IIIB. Dorsal side of penis papilla with three large spines, ventral side of penis papilla with four longitudinal rows of five slightly-bent spines placed at the same level, hence also forming five transverse rows. Female genital system is of the EVELINAE - type, with a long bursointestinal duct, an intestinal bursa and a female genital canal. With a glandular papilla connected to the inferior genital atrium.

Remarks: Also see remarks on P. gracilis .

The known distribution given above is partitioned into two paragraphs, the first one is of the animals originally described as P. clavigera (Fig. 14C2) and the second is of the animals originally described as P. subsalina (Fig. 14C1). Because of the great morphological similarity between these two taxa, Kolasa (1973), although hesitatingly, claimed that P. clavigera and P. subsalina in fact refer to one species, a view we have adopted here. If, in future research, new data become available showing that indeed two species are involved, it will remain clear which species occurs in which localities.

The description of the orientation of the cirrus spines is entirely based on specimens originally assigned to P. clavigera (see Hofsten 1907). According to several authors studying the cirrus of P. subsalina , no specimens were observed with an evaginated cirrus ( Luther 1963; Ax 2008).

Two serially-sectioned specimens of the Swedish Museum of Natural History (SMNH nos 92991–92992) cannot be unambiguously assigned to this species. The specimen SMNH no. 92992 undoubtedly has a copulatory organ of the duplex-type IIIB and a female system of the EVELINAE - type. Unfortunately, it is not entirely clear whether a glandular papilla surrounded by muscles is present, a character typical of P. clavigera . Slide no. 92991 is labelled “ Phaenocora typhlops / subsalina ”, but we did not observe any spines on the copulatory organ. It was collected on the same day (10/7/1935) at Blidö, Almvik, Sweden (see slides) by the same person who collected the specimen on slide SMNH no. 92992, and therefore most probably belongs to the same species. Since both slides can not ensure species recognition, we refrain from designating a neotype for this species.

Figures

FIGURE 1. Photographs of live animals A, P. evelinae. B, P. foliacea from South Africa. C, P. foliacea from India. D, P. aglobulata sp. nov.. E – H, P. gilberti sp. nov.: E – F, pigmentation of the head. G, male copulatory organ. H, female genital canal.

FIGURE 5. Phaenocora evelinae A, habitus of live animal with an invaginated male copulatory organ. B, invaginated male copulatory organ as seen on live animal. C, partly evaginated male copulatory organ as seen on live animal. D, evaginated male copulatory organ as seen on live animal. E, reconstruction on sagittal sections of male copulatory organ (caudal end at the left) F, reconstruction on sagittal sections of female genital system (caudal end at the left). (E – F: HU no. VI. 3.25).