page_title: Kerry slug
section_title: Reproductive system
hierarchical_section_title: Kerry slug / Description / Internal anatomy / Reproductive system
caption_attribution_description: English: Drawing of reproductive system of Geomalacus maculosus.
context_page_description: The Kerry slug or Kerry spotted slug is a species of terrestrial, pulmonate, gastropod mollusc. It is a medium-to-large sized, air-breathing land slug in the family of roundback slugs, Arionidae.
  Adult Kerry slugs generally measure 7–8 cm in length; they are dark-grey or brown with yellowish spots. The internal anatomy of the slug has some unusual features and some characteristic differences from the genus Arion, also part of Arionidae. The Kerry slug was described in 1843—later than many other relatively large land gastropods present in Ireland and Great Britain—an indication of its restricted distribution and secretive habits.
  Although the distribution of this slug species includes south-western Ireland—including County Kerry—the species is more widespread in north-western Spain and central-to-northern Portugal. It is not found in locations between Ireland and Spain. The species appears to require environments that have high humidity, warm summer temperatures and acidic soils with no calcium carbonate. The slug is mostly nocturnal or crepuscular but in Ireland it is active on overcast days.
context_section_description: The Kerry slug is a hermaphrodite, as are all pulmonates. Various authors have depicted its reproductive system: Godwin-Austen (1882), Sharff (1891), Simroth (1891, 1894), Taylor (1907), Germain (1930), Quick (1960) and Platts & Speight (1988). Platts & Speight  considered the depiction by Godwin-Austen (1882) to be the most accurate of those by earlier authors; others depicted the atrium too short.
  The ovotestis—a combination of ovary and testis—is small, compact and darkly pigmented. The hermaphroditic duct, where sperm is stored, is long and convoluted, and ends in a small, spherical, seminal vesicle. The albumen gland, which produces albumen for the eggs, is elongated and shaped like a tongue. The ovispermatoduct, along which both eggs and sperm pass, is greatly twisted. This turns into the free oviduct after the vas deferens carrying the sperm branches off. The free oviduct is long and consistently thin. It opens into the atrium near the genital pore, where the muscular atrium is greatly but irregularly enlarged and connected by muscle fibres to the oviduct.
  The vas deferens is long, complexly twisted, and rolled in a bundle. The bursa copulatrix for digesting spermatophore and sperm—earlier literature refers to this as the spermatheca—is globular and has a short bursa duct. There is a long retractor muscle from the bursa duct, its other end is anchored near the tail of the slug at the midline. The vas deferens and the bursa duct open nearly together into the far extremity of the atrium, the duct into which both the male and the female systems open and which connects to the outside via the genital pore. A special feature of the genus Geomalacus, is the extremely elongated atrium. The elongated portion of the atrium further from the genital pore than the insertion of the oviduct is termed the atrial diverticulum. In Geomalacus, the penis and its penial retractor muscle have been lost. The atrial diverticulum has been proposed to be the functional equivalent, homoplasy) of a penis, acting as a copulatory organ. It is presumed that the bursa retractor muscle retracts the atrial diverticulum.
  In Geomalacus maculosus, the atrial diverticulum is longer than the bursa duct; this situation is reversed in Geomalacus anguiformis.
  Godwin-Austen noted that the part of the atrium just inside the genital pore—he called this region the "vagina"—has "a curious arrangement" of flattened folds. The central part, situated close to the genital pore, has a pointed end. He compared this to the calcareous darts in other genera; on the preceding pages he had described such structures in the Asian slug genus Anadenus).
caption: The reproductive system illustrated by Godwin-Austen (1882).[14] The large mass on the right is albumen gland, the mass on the lower part right is the ovotestis, the oval shape at the left is the bursa copulatrix. Mantle edge and atrium is at the top.
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