Smacigastes Ivanenko & Defaye
Creators: name: Gollner, Sabine
name: Ivanenko, Viatcheslav N.
name: Arbizu, Pedro Martinez
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Harpacticoida
Tegastidae
Smacigastes

description: Genus Smacigastes Ivanenko & Defaye
Type species Smacigastes barti sp. nov.
Type material
Holotype dissected Ψ, 19 slides (nr. SMF 31411) Paratype 1: dissected ɗ, 13 slides (nr. SMF 31412) Paratype 2: Ψ (nr. SMF 31413)
Paratype 3: ɗ (nr. SMF 31414)
Paratype 4: Ψ (nr. SMF 31415)
Paratype 5: ɗ (nr. SMF 31416)
Paratype 6: Ψ (nr. SMF 31417)
Paratype 7: ɗ (nr. SMF 31418)
Paratype 8: dissected copepodite stage V, 3 slides (nr. SMF 31419) Paratype 9: Ψ (nr. OLML 2007/199)
Paratype 10: ɗ (nr. OLML 2007/200)
Paratype 11:Ψ (nr. OLML 2007/201)
Paratype 12: ɗ (nr. OLML 2007/202)
Paratype 13: copepodite stage V (nr. OLML 2007/203)
Type locality
East Pacific Rise (EPR); 9°50.447´N, 104°17.493´W; 2500 m depth. The site Tica is located on the EPR between the Clipperton and Sequeiros transform faults. The site was colonized by the giant tubeworm Riftia pachyptila in 1997 (Fornari et al. 2004). Type material was collected from artificial substrates (PVC hoses) deployed in 2002, and recovered one year later (see Govenar & Fisher 2007).
Etymology
The species is named in honor of Breea Govenar who designed the artificial devices from which specimens were collected (BART: Breea´s Artificial Riftia Tubes).
Female
Body (Fig.1 a, 1b, 2a) laterally compressed, weakly chitinized, with short sensilla and few pores. Total length of female holotype (rostrum to posterior margin of telson) 420 µm, greatest width 180 µm. Rostrum rounded and prominent (Fig. 1 a). Prosome 4­segmented (cephalothorax and 3 somites bearing legs 2 to 4) (Fig. 2a). Urosome (Fig. 2b) 5­segmented: first urosomite with leg 5, genital­double somite with ventral depression and one gonoporus covered by flap of the minute leg 6 (Fig. 1 c, 5b, 5c), and 2 postgenital somites plus telson with furca. Furca 3 times as long as wide, with 7 setae of different length (Fig. 2c).
Antennule (Fig. 2d) 7­segmented; formula of setation: 1, 10, 9, 3+aesthetasc, 6, 4, 6+aesthetasc.
Antenna (Fig. 2e) with small coxa and elongate basis with 1 seta and a field of cuticular spinules. Exopod 2­segmented, proximal segment with 1 inner setae, distal segment with 3 apical setae; endopod 2­segmented, proximal segment with 1 median seta, distal segment with 4 inner setae, 6 terminal setae and a hyaline frill subdistally on outer margin.
Labrum (Fig. 2a) projecting over shield of cephalothorax in lateral view.
Mandible (Fig. 3 a) with gnathobase (not shown); palp 2­segmented, with 2 distal setae on basis and 1­segmented endopod bearing 1 outer and 3 terminal setae.
Maxillule (Fig. 3 b, c) with praecoxal arthrite bearing 8 spines; coxal endite with 1 seta; exopod with 2 setae; basis elongate with 1 median and 4 terminal setae.
Maxilla (Fig. 3 d) syncoxa with two endites, proximal endite with 1, distal endite with 3 spines. Allobasis with 3 lateral setae, two subdistal and one apical spine.
Maxilliped (Fig. 3 e, f) 3­segmented, subchelate; syncoxa elongated with 1 distal seta; basis with 2 rows of spinules; endopod 1­segmented, produced into a strong claw, with 2 proximal setae and an inner row of short spinules.
Swimming legs 1–4 biramous; armature formula as in Table 1.
FIGURE 2. Smacigastes barti sp. nov. Ψ holotype LM drawings: A, habitus, lateral (labrum indicated by arrow); B, urosome, ventral; C, furca, ventral; D, antennule (a seta on 2nd segment broke and is indicated by a circle); E, antenna (frill indicated by arrow). Scale bars A 100 µm; B–E 50 µm.
Leg 1 (Fig. 4 a) with 1­segmented rami.
Leg 2 and leg 3 (Fig. 4 b, 4c) with 3­segmented endopods and 2­segmented exopods; proximal segments of exopods elongated, derived by fusion of former proximal and middle segments.
Leg 4 (Fig. 4 d) with 3­segmented rami. Distal exopod segment with an inner seta slightly modified into a spine (Fig. 5 a).
Leg 5 (Fig. 5 b) with baseoendopod and exopod; baseoendopod with 1 basal outer seta, 3 inner setae, 1 terminal spine, and 1 small terminal outer seta; exopod with 3 outer elements (proximal seta­like; middle and distal ones spine­like), and 2 terminal spines.
Leg 6 a small flap with 1 minute seta (Fig. 5 c).
Single egg sac with three eggs, located ventrally between fifth legs (Fig. 1 b, 1c, 2a).
Male differs from female in the following:
Length of paratype 1 (Fig. 1 d, 6a) 325 µm; greatest width 150 µm. Genital­double somite (Fig. 1 e, 5e) produced ventrally into a large, elongated prominence bearing a distally asymmetrical genital flap representing leg 6.
Antennule (Fig. 6 b) 10­segmented; setation formula as follows: 1, 10, 6+aesthetasc, 1, 7+aesthetasc, 1, 2, 1, 4, 7+aesthetasc.
Leg 5 (Fig. 5 d) 2­segmented; basis with 1 outer seta, exopod with 1 outer proximal seta, 1 outer subdistal spine, and 2 terminal spines.
Leg 6 (Fig. 1 e, 5e) a membranous genital flap on the left side.
One spermatophore stored inside the genital­double somite (Fig. 5 e).
Copepodite stage V
Leg 2 (Fig. 6 c) and Leg 3 (Fig. 6 d) consist of 3­segmented exopods (in contrast to adult) and 2­segmented endopods (shortly before division into the adult 3­segmented endopod).
description: Published as part of Gollner, Sabine, Ivanenko, Viatcheslav N. & Arbizu, Pedro Martinez, 2008, A new species of deep­sea Tegastidae (Crustacea: Copepoda: Harpacticoida) from 9 ° 50´N on the East Pacific Rise, with remarks on its ecology *, pp. 323-326 in Zootaxa 1866 on pages 324-332, DOI: 10.5281/zenodo.183742