Minyaspis faroni, (Totton, 1940)

Brickner, Itzchak, Koplovitz, Gil, Simon-Blecher, Noa & Achituv, Yair, 2022, Lost and found: Totton’s Minyaspis faroni revived and molecular evidence of paraphyly of Oxynaspis and Minyaspis, Journal of Natural History 56 (37 - 40), pp. 1459-1473 : 1463

Minynaspis faroni ( Totton, 1940)

Diagnosis

Capitulum elongated, partly covered by five valves, elastic cuticle between valves. Valves thin and fragile, tergum not calcified along carinal and tergal margins, occludent margin lobed. Scutum trilobed. Carina arched, externally convex, basal end truncate.

Description

Surface of whole animal covered by host soft tissue, host spines that look like small protuberances on surface. Cirri soma red, like colour of host ( Figures 1 , 2 ).

Capitulum elongated, height about 2 times width ( Figure 4 ). Capitular valves thin and fragile, growth lines on outer surface, separated, elastic chitinious layer between plates. Tergum ( Figure 5a,b ), occludent margin lobed, gap between apical lobes and one or three basal lobes, inner surface flat. Scutum ( Figure 5b,c ), trilobed, occuldent and basal margin form a triangular projection, lateral margin elongated S-shaped, adductor muscle pit shallow. Carina ( Figure 5e ) slender, bow-shaped basal margin truncate, basal margin slightly forked, umbo located at about lower one-fifth of total height.

Prosoma ( Figure 6 ) without filamentary appendages, ovarian tissue beneath somatic body inside capitulum. Labrum bullate, row of short spines on distal margin ( Figure 7a,b ). Palpi ( Figure 7a ) elongated tapered, outer margins with long setae on distal half and few simple setae on inner margin. Maxilla I ( Figure 7c ) rounded, dense simple setae on upper margins. Maxilla II ( Figure 7d ) quadrangular, upper angle with a large and strong spine followed by three smaller spines, deep notch between upper and lower part, below notch 15–17 spines. Short setae in notch and among spines. Long setae on lower margin. Mandible ( Figure 7e ) with five teeth, fourth and fifth acute; 10 to 15 simple, fine, long setae scattered on upper margin, short setae in gaps between teeth. Surface of mandible with short spines.

Cirri ( Figure 8 ): Cirrus I ( Figure 8a ) with anterior ramus longer than posterior rami, with 7 segments and 9–10 segments, respectively (counts from two specimens), short conical projection on front of basis ( Figure 8a,b ), setae simple. Cirrus II ( Figure 8c ) with subequal rami, anterior 12–13, posterior 13–14, setae simple. Cirri III– VI stout, with subequal rami, segment number, setae on segments simple cirrus III ( Figure 8d ) (anterior ramus 15–16 segments, posterior ramus 16 segments), cirrus IV ( Figure 8e ) anterior ramus 17–16, posterior ramus 16 segments . Cirrus V ( Figure 8f ), anterior ramus 15 segments, posterior ramus 16 segments, cirrus VI ( Figure 8f ) anterior ramus 18, 19 ). Pedicel without basidorsal point. Short simple setae scattered on penis, tip of penis with short, simple-type setae. Caudal appendages absent.

Figures

Figure 1. Minyaspis faroni. In situ photography, specimen with extended cirri.

Figure 2. A colony of the antipatharians Antipathes cf. lentipinna, specimens of Minyaspis faroni attached to the basis of the colony.

Figure 4. Minyaspis faroni. Whole specimen, isolated shell plate (from the same specimen) superimposed on surface of capitulum. Scale bar= 3mm.

Figure 5. Minyaspis faroni. Isolated shell plate, tergum and scutum outside and inside view, carina side view.

Figure 6. Minyaspis faroni. Soma lateral view. Labrum (L) and palpus (P) are indicated. C1–C6: cirri.

Figure 7. Minyaspis faroni. Mouth parts. (a) Labrum and palpus. (b) Tip of labrum. (c) Maxilla I. (d) Maxilla II. (e) Mandible.

Figure 8. Minyaspis faroni. Lateral view of cirri. (a) Cirrus I. (b) Cirrus I, basal segment. (c) Cirrus II. (d) Cirrus III. (e) Cirrus IV. (f) Cirrus V. (g) Cirrus VI and penis.