Fendia, Rodriguez, 2023

Fendia View in CoL n. gen.

Diagnosis

Small worms, with a short prostomium and secondary annulation in the pre-clitellar segments. Muscular pharynx well developed both dorsal and ventrally. Posterior lateral blood vessels absent. Nephridia with long postseptal duct, present from segment XIII. Testes paired in both IX and X. One pair of ovaries in XI. Male pores open in X, posterior to ventral chaetae, surrounded by a ring of glandular cells. One pair of atria in X with cross-hatched musculature, and a muscular penial bulb where penis protrudes from the inner epithelium of the atrial duct. Two clusters of prostatic cells, connected to opposite sides of the atrium by stalks. Small sperm funnels on 9/10 and 10/11. Spermathecae paired in segments XI (ovarian) and XII (post-ovarian). Spermathecal pores posterior to ventral chaetae. Female pores in 11/12.

Type species: Fendia cantabrica View in CoL n. sp.

Remarks

There are only two lumbriculid genera that share with Fendia n. gen. the semiprosoporous condition of the male duct together with the presence of two pairs of spermathecae in the postatrial segments: Trichodrilus Claparède, 1862 and Eremidrilus Fend & Rodriguez, 2003 . The absence of a filiform proboscis, and the irregular shape and structure of the atrium clearly separate Fendia n. gen from the Nearctic genus Eremidrilus . The main distinction of Fendia n. gen. from Trichodrilus , as well as from other semiprosoporous taxa, is the complex male duct structure (cross-hatched, thick atrial musculature, muscular penial bulb, protrusible penis, a ring of glandular cells at the male pore), and in particular the presence of prostatic glands forming well-separated clusters joining opposite sides of the atrium through thick passages. Specifically, the covering of the atria by prostatic cells, either in a diffuse and continuous manner, or forming several small clusters of prostatic cells that join the atrial ampulla separately, is the common condition in Lumbriculidae . The prostatic glands organized in few bundles that join the atrium by short stalks were previously described by Fend & Ohtaka (2004) in the prosoporous lumbriculid Yamaguchia Fend & Ohtaka.