Minyaspis welchi, Van, Robert J. & Dekelboum, Allen M., 2011

Van, Robert J. & Dekelboum, Allen M., 2011, Oxynaspididae (Crustacea, Cirripedia): phylogenetics and evolutionary ecology, with descriptions of three new genera and six new species, Zootaxa 3103, pp. 1-32 : 22-25

Minyaspis welchi sp. nov.

Figures 13 , 14

Material examined. Holotype: CASIZ 110150, 1 complete intact specimen, attached to Antipathes sp. ( CASIZ 113590); Fiji Is, Great Astrolabe Reef, W of Vanuakula I., small pass through reef; 15–18 m; 5 June 1998; coll. Robert Van Syoc (RVS-409). Paratypes: CASIZ 110149, 1 specimen, plates on SEM stub; same locality as holotype. CASIZ 110129, 1 specimen; same locality as holotype. CASIZ 110131, 1 specimen; same locality as holotype. CASIZ 110169, 1 specimen, mouthparts and cirri on glass microscope slide; Fiji Is, Great Astrolabe Reef, S of Herald Passage, outside of reef, under ledge; 18° 46.26’ S, 178° 27.79’ E; depth: 24 m; 4 June 1998; coll. Robert Van Syoc (RVS-405). CASIZ 110170, 1 specimen; same locality as CASIZ 110169. CASIZ 113623, 1 specimen; same locality as CASIZ 110169. CASIZ 113626, 1 specimen; Fiji Is, Great Astrolabe Reef, NE corner, under overhang; 18° 42.41’ E’ 178° 32.32 S; depth: 18 m; 23 June 1998; coll. Robert Van Syoc (RVS-452). CASIZ 113627, 1 specimen; same locality as CASIZ 113626. CASIZ 110148, 8 specimens; same locality as holotype. SIO-BIC C11217, from CASIZ 110148.

Diagnosis. Small bumps or protuberances on exterior of all plates ( Fig. 13 ); carina forming about 90° angle at umbo, basal end broadly, roundly forked, ends truncated; tergal occludent margin with large, broad, round teeth along entire margin; scutal occludent margin with a few rounded teeth above umbo, basal margin rising steeply to occludent margin.

Description. Capitulum ( Fig. 14 A) with large non-calcified area between scutum and carina; capitular height greater than twice its width; low growth ridges and small protuberances on all plates; covered with chitinous, golden-brown epicuticle.

Scutum ( Fig. 13 F,G; Fig. 14 A) irregularly shaped, not quadrangular; umbo subcentral, not on occludent margin; separated from carina by wide non-calcified area; near tergum at slightly more than one-half length of tergum; occludent and basal margins forming angle greater than 90°; basal margin broadly convex with very shallow concavity near occludent margin; occludent margin coincident with mantle margin; occludent edge irregular in upper half, with large tooth-like protuberances; carinal margin shallowly concave; adductor muscle pit shallow.

Tergum ( Fig. 13 D,E; Fig. 14 A) broadly triangular; margins nearly touching carina and scutum; umbo at apex; scutal margin smooth with shallow notch above scutal apex; occludent edge irregular with large, tooth-like protuberances.

Carina ( Fig. 13 A,B,C; Fig. 14 A) bent in upper portion, line from apex to umbo passing outside of carina, similarly line from apex to basal/peduncular margin not passing through scutum; umbo between basal one-fifth and one-third; basal margin deeply forked, extending more than halfway across peduncle; longer than scutum; width narrowest at umbo; extending up less than one-half length of tergum; with shallow inflection between basal margin and umbo.

Labrum bullate.

Mandible ( Fig. 14 B) with 5 teeth, first largest, second about half length of first, third and fourth slightly shorter than second, fifth about half length of third and fourth; face of mandible, superior and inferior margins setose.

First maxilla ( Fig. 14 C) with deep notch in superior half of cutting edge; 2 large, long spines and few shorter spines above notch, many shorter spines below notch, some approaching size of large spines above notch; face of maxilla, superior and inferior margins setose.

Cirrus I ( Fig. 14 D) with anterior ramus shorter than posterior, remaining cirri with rami about equal. Setae simple. Cirral counts are as follows:

CI CII CIII CIV CV CIV Ant. 9 16 - 21 21 20 Post. 10 16 16 18 20 20

Ant. 8 13 17 16 19 20 Post. 9 14 16 18 - 20 Caudal appendages lacking. Filamentary appendages lacking on either side at base of cirrus I. Dorsal filamentary appendages lacking.

Etymology. Named in honor of Captain Dennis Welch, a friend and supporter of research at the California Academy of Sciences.

Remarks. Minyaspis welchi sp. nov. is most similar morphologically to M. aurivilli ( Stebbing, 1900) and M. opreskoi sp. nov. It differs from M. aurivilli in states for 8 characters and from M. opreskoi in states for 12 characters in our data matrix. The three most obvious differences are that M. welchi has 1) a basally forked carina, 2) with the basal forked ends extending more than halfway across the peduncle, and 3) the carina extends along less than one-half the length of the tergum.

Figures

FIGURE 13. Minyaspis welchi sp. nov. Paratype CASIZ 110149. Carina, dorsal view (A), oblique view (B), side view (C). Tergum exterior (D), interior (E). Scutum exterior (F), interior (G). Scale bar equals 750 µm for A, B, C; 600 µm for D, E, and F; 850 µm for and G.

FIGURE 14. Minyaspis welchi sp. nov. Paratype CASIZ 110170; outline of whole specimen showing general arrangement of plates in relation to each other (A), plate details are not shown in this simple outline drawing, see SEMs in Fig. 13 for plate details. Paratype CASIZ 110169; Mandible (B), Maxilla 1 (C), Cirrus I (D). Holotype CASIZ 110150; whole specimen, with host tissue covering capitulum (E).