Turbellarian taxonomic database
Daku riegeri Diagnosis
Living specimens ~500 µm long and ~150 µm wide (Fig. 3A). Anterior and posterior ends rounded.
Epidermis without conspicuous coloration in transmitted light. Epidermis completely ciliated. Rhabdoid
glands present in distinct longitudinal rows. Frontal organ well developed. Mouth opening on ventral surface,
middle of body (Fig. 5A).
Ovaries paired, ventral; extends from mouth posteriorly to seminal bursa. Testes paired, lateral to
ovary; extend from level of statocyst to seminal vesicle (Fig. 5A).
Common gonopore ventral at posterior end of body opens to ciliated atrium surrounded on posterior and
lateral sides by circularly oriented muscle fibers (Figs. 4A, 5B, C, 6A, C). Atrium branches anteriorly to
male copulatory organ and dorsally to vagina (Figs. 5B, C). Behind male copulatory organ, vagina filled with
large, spindle-shaped, erythrophilic glands that are grouped in a fan-like arrangement when viewed ventrally
or dorsally (Figs. 3B, 4B, 5A–D). Vagina passes over male copulatory organ to seminal bursa positioned
immediately anterior to seminal vesicle (Figs. 5D, 6B). Wall of seminal vesicle composed of many small cells
and may contain some spots of concentrated actin (Figs. 5D, 6B).
Male copulatory organ composed of seminal vesicle that surrounds sperm and penis (Figs. 3B, 4B, 5B). Muscular
wall of seminal vesicle with regularly spaced circular and longitudinal fibers (Fig. 6A). Sperm fill
majority of seminal vesicle space; sperm at distal end aligned in parallel. Bowl-shaped, glandular penis,
composed of lamellae-like cells that stain metachromatically for glycoseaminoglycans and positioned at the
distal end of seminal vesicle (Figs. 4A, B, 5B).
[From Hooge MD, Tyler S (2008): 6-9]
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