Sparganophilus sp

Sparganophilus sp 02

Figures 7D–F View FIGURE 7 ; 9C View FIGURE 9

Material: GTIC-11654; One adult, in sediments on the banks of the Tyger River , Calhoun Experimental Forest , Union, Union Co., South Carolina, USA. Col. R. Carrera-Martínez, M.K. Taylor, M.A. Callaham, Jr. & G. Chapman. 18. MAY.2017. (34.64073°N, 081.69579°W) GoogleMaps .

Diagnosis: Length 31 mm. Dorsal pores absent. Clitellum saddle-shaped in xv–xxiii, ventral limit in b. Tubercula pubertatis continuous in xviii–xix, xx, band-shaped, ventral limit dorsal to b. Setae closely paired: ab = cd, aa <bc <dd. Spermathecal pores between cd, in 5/6–7/8, minute. Pores of prostate-like glands in xx–xxiii. Secondary annulation absent. Genital tumescences surrounding ab weakly developed in xx–xxii. Intestinal origin in viii. One pair of spermathecae per segment in of vi–viii, spermathecal structure moderately differentiated into ampulla and duct, smooth, duct tubular, three times as long as the globular ampulla. Prostate-like glands in xx–xxiii and auxiliary prostate-like glands absent. First nephridia in xiii, tubular bladder, wide u-shaped vesicle.

Description: Length of unamputated preserved specimen 31 mm. Diameter in x 1.8 mm, in the clitellum, 2.8 mm. Number of segments, 104. Body ovoid in cross-section anteriorly, ventrally flattened at the clitellum, quadrangular in cross-section posterior to the clitellum. Preserved specimens with a pale whitish coloration, clitellum darker than body. Cuticle with a strong purple iridescence. Prostomium zygolobic. Dorsal pores absent. Spermathecal pores in intersegmental furrows 5/6–7/8 between cd, small. Female pores in xiv, anterior and ventral to aa, minute but visible. Male pores lateral to b in xix, equatorial, at the dorsal margin of tubercula pubertatis. Clitellum in xv–xxiii saddle-shaped, ventral limit in b. Tubercula pubertatis continuous xviii–xix at the right side, xviii–xx at the left, band-shaped, ventral limit dorsal to setae line b. Prostate-like pores in xx–xxiii next to b, on small porophores. Nephridiopores anterior to ab, closer to a, starting in segment xiii, minute but visible. First setae in ii, lumbricine, setae closely paired. In x aa:ab:bc:cd:dd = 4.50:1.00:6.50:1.00:7.50, in xxx = 5.00:1.00:6.50:1.50:7.50. Setae cd not observed in clitellum. Secondary annulation absent. Genital tumescences surrounding ab in xx–xxii, weakly developed. Post-setal dark spots visible just ventral to c, in a regular in i–xiv. One dorsal depression in the equator of peristomium.

Septa 6/7–7/8 thickened. Pharynx ends in segment iv, joining a small esophagus. Intestine originates abruptly in viii. Intestinal caeca, typhlosole, calciferous glands, and gizzard absent. One pair of spermathecae in each of vi–viii, without diverticulum. Spermathecal structure moderately differentiated into ampulla and duct, all similar size. Duct about three times as long as than the ampulla, tubular, wide. Ampulla small, globular, smooth, ovate. Duct connects to the intersegmental furrows level with the setal line cb. Spermathecae located between a weak muscular fiber originating anteriorly in the intersegmental section of the esophagus and connecting posteriorly to the intersegmental-septum joint. Ovaries in xiii, free, string-like. Oviduct connects in segment xiv, anterior to a. Testes free in x and xi. Epididymis not observed. Seminal vesicles, free in xi, and xii, small. Vas deferens within muscular body wall. Tubular, prostate-like glands in xx–xxiii, greatly reduced. Auxiliary prostate-like glands absent. One pair of holonephridia per segment, starting at xiii. Holonephridia tubular, bladder composed of highly coiled tubules dorsally, ventrally with a narrow u-shaped vesicle, all same size. Holonephridia of xiv attached to 13/14 septa. A vessel stoma is attached at the distal part of the vesicle. Paired moniliform hearts in vii–xi, all similar size. Dorsal and ventral vessel complete, and simple. Paired lateral vessel present, joining dorsal vessel in xiii, filiform.

Remarks: Sparganophilus sp 02 superficially resembles S. pearsei sarasotae on its size, spermathecae location, and clitellum position, but differs from this and all sparganophilids by having reduced prostate-like glands in xx– xxiii, extent of the tubercula pubertatis, having paired filiform lateral vessels joining dorsal and ventral trunks in xiii, and having its intestinal origin in viii. Additionally, with only 104 segments and a length of 31 mm, this is potentially the smallest species of Sparganophilus . We decided to refrain from naming this species until additional material and molecular data are available.