Taxonomy of North European Lumbricillus (Clitellata, Enchytraeidae)
Author
Klinth, Marten J.
Author
Rota, Emilia
Author
Erseus, Christer
text
ZooKeys
2017
703
15
96
http://dx.doi.org/10.3897/zookeys.703.13385
journal article
http://dx.doi.org/10.3897/zookeys.703.13385
1313-2970-703-15
9BAAB4A5CDE1493B8A0413D8F301E198
Lumbricillus tuba Stephenson, 1911
Fig. 16
Lumbricillus
tuba
Stephenson, 1911: pp. 42-46, figs 5
a-b
, pl. I, figs 6-8;
Nielsen and Christensen 1959
: p. 105, fig. 131;
Erseus
et al. 2010
;
Klinth et al. 2017
.
Type material.
Typus amissus (Nomenclatura Oligochaetologica). Type locality: Firth of Clyde, Millport, Island of Cumbrae, United Kingdom (
Stephenson 1911
). We did not designate a neotype as we do not have material from the type locality.
Material examined.
ZMBN 107916 (CE22614), one mature specimen from Norway. For information on specimen collection locality and GenBank accession number see Appendix 1. Note that this specimen is the only sexually mature available for this study, but additional (immature) worms were studied genetically by
Klinth et al. (2017)
.
Description.
White to grey worm. Length (fixed worm) more than 4.8 mm (amputated specimen), first 15 segments 2.0 mm long, width at clitellum 0.39 mm. More than 39 segments. Chaetae slightly sigmoid (Fig. 16A). Dorsal bundles with 2-3 chaetae anterior to clitellum, 2-3 chaetae in postclitellar segments. Ventral bundles with 3-4 chaetae anterior to clitellum, 2-3 chaetae posteriorly. The
worm's
longest measured chaeta 48
µm
long, about 3
µm
wide. Clitellum extending over
XII-
1/2XIII. Head pore not observed. Epidermis with transverse rows of gland cells.
Coelomocytes numerous, 20
µm
long, spindle-shaped, oval, round, granulated. Paired pharyngeal glands present in IV, V and VI (Fig. 16B). Dorsal vessel originating in XII. Nephridia not observed. Brain longer than wide, further shape unclear.
Male genitalia paired (Fig. 16D). Testes originating in XI, extending forwards into IX, with testis sacs forming regular club-shaped lobes. Sperm funnels in XI, 120
µm
long, 105
µm
wide, making them slightly longer than wide, funnels tapering towards vasa deferentia. Most of vasa irregularly coiled in XII, 10
µm
wide. Penial bulbs round, 85
µm
in diameter. Ovaries in XII. Two mature eggs present.
Spermathecae (Fig. 16C) in V, club-shaped, with distinct ampulla. Ectal duct as long as ampulla, abruptly widening into oval ampulla. Sperm circularly arranged in ampulla. Spermathecae 120
µm
long, 85µm wide at widest part of ampulla. Gland cells surrounding ectal pore, forming compact mass, whole glandular body 75
µm
in diameter at its widest part. Three midventral subneural glands in
XIII-
XV, 85µm, 90
µm
and 85
µm
long, respectively.
Figure 16.
Lumbricillus tuba
. A Chaetal bundle B Anterior body C Spermatheca D Other genitalia. Abbreviations under general notes. Scale bars: 100
µm
.
Geographical distribution including BOLD data.
Genetically identified from Norway and Sweden. Also described from Denmark and the United Kingdom. BIN-number: BOLD:ACQ1913.
Remarks.
Our specimen matches the original description by
Stephenson (1911)
well in most characters, including the shape of the spermathecae and the proportions of the sperm funnels. However, its body size was smaller and the chaetae per bundle slightly fewer than in the original description.
Lumbricillus tuba
is genetically most closely related to the
L. pagenstecheri
group (including
L. viridis
), but it is morphologically most similar to
L. scandicus
sp. n. described below.