Zelinkaderes submersus (Gerlach 1969)

Zelinkaderes submersus

Cateria submersa Gerlach, 1969:120.

DIAGNOSIS.—Zelinkaderes, adult trunk length 576–720 μm, general trunk width about 15 percent of trunk length, with middorsal spines on segments 6, 8, 10–13 each nearly one-third longer than length of segment of origin; middorsal cuticular scars on segments 3 and 4, subdorsal cuticular scars on segment 12; cuspidate spines ventrolaterally on segments 4, 6–9, and 11, elevated on segment 10; acicular spines ventrolaterally on segment 10 and as lateral terminal spines on segment 13; acicular spines lateroventrally on segments 11, 12, and as lateral terminal accessory spine on segment 13; lateral terminal spines longer than lateral terminal accessory spines.

REDESCRIPTION.—Adult, paratypic female (Figures 70, 71; original type designation (Gerlach's number “301g,” RH 1225.3, USNM 063089) 665 μm long. The maximum sternal width is estimated to be about 15 percent of the trunk length. The standard width, based on the distance between the lateral margins of the cuspidate spines of segment 11 is 88 μm, 13.2 percent of the trunk length.

Segment 2 is estimated to be about 25 μm long and appears to have no distinct articulation with segment 3, individual placids (Figure 74, pl) are weakly developed; the midventral placid is about twice as wide as the remaining 15 placids.

Segment 3, 50 μm long, is surrounded by a complete ring of cuticle. The anterior margin, adjacent to the placids, lacks cuticular hairs and the internal striate pattern (visible only with phase contrast optics; Figure 77, st), typical of areas of cuticular hairs; the remaining portion of the segment is hirsute with a pectinate fringe at the posterior margin. No pachycyclar area is evidenced on any of the segments with the exception of the anteroventral margin of segment 12 of the female; the cuticle is uniformly thin except for the arthrocorium.

Segment 4 is 54 μm in length and, like segment 3, is surrounded by a complete ring of cuticle. A prominent middorsal cuticular scar (a pore leading to a middorsal gland) is present. A transverse row of three patches of less hirsute cuticle are located anterodorsally. On the ventral surface there are two small (25 μm) cuspidate spines.

Segment 5 is 60 μm in length. A middorsal cuticular scar is present as are three paired patches of less hirsute cuticle noted on segment 4. Beginning with this segment, there is a midventral fissure where the lateral edges of the cuticle meet.This area appears slightly thicker than the remainder of the cuticle (Figure 70).

Segment 6 is 60 μm in length. There is no middorsal cuticular scar. A middorsal spine, 96 μm in length, extends from a slight indentation on the posterior margin of the segment. Sensory spots are present on either side of the base of the middorsal spine as are adjacent to all middorsal spines. Ventrolateral cuspidate spines, 30 μm long, are present.

Segment 7 is 62 μm long. No middorsal spine is present, ventrolateral cuspidate spines are 32 μm long.

Segment 8 is 65 μm long and similar to segment 6. The middorsal spine is 118 μm long, the ventrolateral cuspidate spines are 33 μm long.

Segment 9 is 70 μm long and similar to segment 7. The ventrolateral cuspidate spines are 36 μm long.

Segment 10 is 88 μm long. The middorsal spine is 102 μm long. Acicular spines (90 μm long) are present ventrolaterally with cuspidate spines (40 μm long) dorsally adjacent. Both spines are slightly elevated above those of anterior and posterior segments. On the ventral surface of the female there is a prominent pore anteromesial to the base of each acicular spine.

Segment 11 is 78 μm long. The middorsal spine is 115 μm long. Ventrolateral cuspidate spines (Figure 77), 34 μm in length, are in the position of the acicular spines of the previous segment and are accompanied by acicular spines, 91 μm long. The prominent pores on the ventral cuticle of the female are slightly more mesially situated than in segment 10.

Segment 12 (Figures 70, 71, 77, 79) is 70 μm long and has an acicular middorsal spine typical of the females of this genus. Lateral to the base of the middorsal spine on segment 12 are cuticular scars. Acicular spines, 70 μm long, also are present lateroventrally, in a slightly elevated position (Figure 79). Like the middorsal spine of this segment, this lateral spine is flexible in the male (Figures 72, 73, 78).

Segment 13 is 68 μm long. The middorsal spine is 220 μm long, extending over one-third the length of the midterminal spine directly posterior to it. The lateral terminal spines are 142 μm long, 21.4 percent of the trunk length, longer than the lateral terminal accessory spines. The lateral terminal accessory spines are 114 μm long, 17.1 percent of the trunk length. The LTAS/TL is 80.1 percent. The midterminal spine is 500 μm long, 75.2 percent of the trunk length. In the female, near the anterior margin on the ventral surface of segment 13, there is an area of thickened pachycyclar cuticle with a prominently arched configuration near the lateral margins (Figures 70, 77). This pachycyclar structure is not evident in males (Figures 72, 73).

The head cannot be described in detail; however, the oral styles (Figures 74–76) appear to be long (70–85 μm) and thin, and the pharyngeal styles are well developed.

The male appears to be similar to the female with the exception of those sexual dimorphic characters already noted.