Prochaetoderma gilrowei, Ivanov & Scheltema, 2008

Ivanov, Dmitry L. & Scheltema, Amélie H., 2008, NMR solution structures of KAP- 1 PHD finger-bromodomain, Zootaxa 1885, pp. 1-60 : 26-27

publication ID	https://doi.org/ 10.13018/bmr11036
DOI	https://doi.org/10.5281/zenodo.5134432
persistent identifier	https://treatment.plazi.org/id/3076EC0B-FF98-FF97-5DAB-FE69FEBB0846
treatment provided by	Felipe
scientific name	Prochaetoderma gilrowei
status	sp. nov.

Treatment

Prochaetoderma gilrowei View in CoL n. sp.

( Figures 1G View FIGURE 1 , 16 View FIGURE 16 , 17 View FIGURE 17 , 18D–F View FIGURE 18 , 24C View FIGURE 24 , 25 View FIGURE 25 ; Tables 1, 2, 4a)

Type material: Holotype USNM 1112619 View Materials . Paratypes: USNM; TAMU ; ZMUM Le1–156 (DGoMCS 4447, station E2b/3); Le1–157 (DGoMB S35/3).

Type locality: Gulf of Mexico, 28°15.16'N, 86°25.07'W, 767 m (DGoMB S42/1, 09.06.2000) GoogleMaps .

Material examined: Gulf of Mexico, 159 specimens ( Table 1); Guiana Basin, 60 specimens ( Table 4a) .

Diagnosis: Small (<2.0 mm), almost cylindrical, glistening, semi-transparent sclerites closely adpressed on trunk, shank short, fringing sclerites in single row, long, many more than twice length of knob; with short, broad shank, posterium 1/3 to <1/2 trunk length; anterium usually slightly everted; junction of shank and knob clearly demarcated. Oral shield sclerites in 2 rows. Trunk sclerites short, thin, symmetrical, with longitudinal axis straight (most) to curved, sharply pointed distally, with distinct distal keel, waist distinct, blade with sharp, fine longitudinal ridges, base with fine longitudinal striations ( Fig. 18F View FIGURE 18 ).

Etymology: Named in honor of Dr. Gilbert Rowe, who provided us with much of the Gulf of Mexico material reported here.

Description: External appearance: Small, to 1.8 mm, many <1.0 mm, almost cylindrical, trunk diameter 0.4–0.5 mm, mid-shank diameter 0.2–0.4 mm, posterium/trunk index varying from 0.33–0.44; holotype length 1.6 mm, anterium 0.1 mm, trunk 1.1 x 0.5 mm, shank 0.2 x 0.4 mm, knob 0.2 mm, posterium/trunk index 0.36;. Oral shield 0.08–0.14 mm in height, sclerites from 4 to 8 in each of 2 rows, those of second row largest ( Fig. 16D View FIGURE 16 ).

Sclerites ( Figs 16E View FIGURE 16 , 17 View FIGURE 17 , 18D–F View FIGURE 18 ): General: Short, thin, symmetrical, less than 170 µm long, 5 µm thick, longitudinal axis to somewhat curved ( Figs 17J View FIGURE 17 , 18D, E View FIGURE 18 ), waist indented, blade narrower than base, thickest at waist and blade, sides of base convex, of blade straight to convex, proximally rounded, distally sharply pointed; keel on blade with fine, sharp ridges, base striated ( Fig. 18D, F View FIGURE 18 ). Oral shield ( Fig. 17A View FIGURE 17 ): straight to curved, tapered basally, thick, to 50 x 15 x 4 µm, thickest proximally. Dorsal to oral shield ( Fig. 17B View FIGURE 17 ): very thin scales, most sub-triangular, to 45 x 30 x <1 µm. Anterium ( Fig. 17C View FIGURE 17 ): either short with curved, narrow base, or with distinct waist, blade and base almost equal in length, to 100 x 30 x 3 µm, blade narrower than base. Dorsal trunk ( Figs 16E View FIGURE 16 , 17F View FIGURE 17 , 18D, E View FIGURE 18 ): as in general description, to 160 x 45 x 5 µm, thickest on keel near waist, blade and base width 30 and 45 µm, respectively. Ventral and lateral trunk ( Fig. 17D, E View FIGURE 17 ): similar to those from dorsal trunk, but most shorter and narrower. Shank ( Fig. 17G View FIGURE 17 ): either broad-based with short blade, 110 x 45 µm, or with narrower base and elongate blade, to 160 x 35 µm, both types thickest on blade. Fringing ( Fig. 17I View FIGURE 17 ): long and slightly curved, to 500 x 8 x 8 µm. Knob ( Fig. 17H View FIGURE 17 ): curved, tapered at both ends, thickest medially, to 140 x 15 x 4 µm.

Radula and jaws: 2 examined. Jaws 310 x 120 µm ( Fig. 16F View FIGURE 16 ); radula teeth 85 µm long, serrated membrane short, about 40 µm, situated further proximally than distally; central plate asymmetrical, to 35 µm ( Fig. 16G View FIGURE 16 ).

Distribution: Continental slope and uppermost rise: Gulf of Mexico 334–1,032 m ( Fig. 24C View FIGURE 24 ), Guiana Basin 508 m and 1,000 m ( Fig. 25 View FIGURE 25 ; Tables 1, 2, 4a).

Remarks: Prochaetoderma gilrowei is distinguish from other Prochaetoderma species by its short cylindrical body with a short, broad posterium. Mid-trunk sclerites are similar to those of P. yongei Scheltema, 1985 but are ornamented, the blade with longitudinal ridges and the base and waist with longitudinal striations ( Fig. 18D, F View FIGURE 18 ).