Echinopsolus parvipes Massin, 1992

Bohn, Jens Michael, 2014, The Antarctic holothurian genus Echinopsolus Gutt, 1990 (Dendrochirotida, Cucumariidae): brood pouches, spermatozoa, spermatozeugmata and taxonomic implications, Zootaxa 3841 (4), pp. 573-591 : 584-585

Echinopsolus parvipes Massin, 1992

( Figs 2e , 4g –i , 6f )

Echinopsolus parvipes Massin, 1992: 179 , figs 1–5.

Echinopsolus splendidus ( Gutt, 1990) comb. nov.

( Figs 1b–d, f , 3d–e , 4a–d , 6g )

Microchoerus splendidus Gutt, 1990: 107 , figs 9–11.

Figures

FIGURE 1. Genital papillae and brood pouches of Echinopsolus spp. a. Male genital papilla (arrowhead) of E. acutus. b–d. E. splendidus. b. Male genital papilla. c. Female genital papilla (arrowhead). d. Brood pouch openings (arrowheads) of a female with retracted tentacles. e. E. acanthocola, brood pouch opening of a female (arrowhead). f. E. splendidus, brood pouch (opened up) with developing juveniles.

FIGURE 2. Ultrastructure (SEM) of spermatozeugmata and sperm cells of Echinopsolus spp. a. Mass of sperm bundles in gonad tubule (opened up) of E. koehleri. b–e. Spermatozeugmata. b. E. acanthocola. c. E. charcoti. d. E. mollis. e. E. parvipes. f–g. Spermatozoa. f. E. acanthocola. g. E. koehleri. Arrows—acrosomes; arrowheads—cylinder shaped mid-pieces.

FIGURE 3. Histology of spermatozeugmata and sperm cells of Echinopsolus spp. a–c. E. acutus. a. Semithin cross section in centre of seminiferous tubule. b. Sperm bundles fill central space of seminiferous tubule. c. Longitudinal section through spermatozeugma showing sperm heads, mid-pieces and flagella. d–e. E. splendidus. d. Mass of sperm bundles. e. Longitudinal section through spermatozeugma. f–g. E. mollis. f. Mass of sperm bundles. g. Longitudinal section through spermatozeugma with poor structure preservation (alcohol conservation, no aldehyde fixation). f—flagellum; m—mid-piece; n—nucleus.

FIGURE 4. Ultrastructure (TEM) of spermatozeugmata and sperm cells of Echinopsolus spp. a–d. E. splendidus. a. Overview of ripe sperm cells and spermiogenesis-stages. b. Different regions of sperm cells in oblique cutting planes. c. Nuclear apex with cup-shaped indentation containing acrosomal complex. d. Cross section through mid-piece at level of centriolar satellite complex. e. E. acanthocola, longitudinal sections through sperm-cell head and mid-piece. f. E. koehleri longitudinal section through sperm-cell head and mid-piece. g–i. E. parvipes. g. Close up of nuclear apex with acrosomal vesicle anchored by actomere and subacrosomal plate (arrowheads) in periachrosomal material. h. Close up of the mid-piece region in axial section plane. i–k. Cross sections through mid-pieces at level of centriolar satellite complex. i. E. parvipes. j. E. charcoti. k. E. koehleri (premature). a—acrosomal vesicle; dc—distal centriole; f—flagellum; m—mid-piece; n—nucleus; p—periacrosomal material; pc—proximal centriole; s—spermiogenesis-stages; sc—centriolar satellite complex.

FIGURE 6. Variability of tube feet arrangement of Echinopsolus spp. a. E. acanthocola, lateral and ventral view. b. E. acutus, dorsal and ventral view. c. E. charcoti, lateral and ventral view. d. E. koehleri, lateral and ventral view. e. E. mollis, dorsal and ventral view (tentacles retracted, mouth to the left). f. E. parvipes, lateral and ventral view. g. E. splendidus, lateral and ventral view (tentacles retracted, mouth to the left).