Cyclacanthia rethahofmeyri Samaai, Kelly, Payne

Samaai, Toufiek, Kelly, Michelle, Ngwakum, Benedicta, Payne, Robyn, Teske, Peter R., Janson, Liesl, Kerwath, Sven, Parker, Denham & Gibbons, Mark J., 2020, New Latrunculiidae (Demospongiae, Poecilosclerida) from the Agulhas ecoregion of temperate southern Africa, Zootaxa 4896 (3), pp. 409-442: 435-437

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Cyclacanthia rethahofmeyri Samaai, Kelly, Payne

sp. nov.

Cyclacanthia rethahofmeyri Samaai, Kelly, Payne   and Ngwakum sp. nov.

( Fig. 15B View FIGURE 15 , Tables 6, 7)

Material examined. Holotype SAMC-A090895, Amathole region Stn 3872, Eastern Cape, 32.950° S, 28.066° E, 40.5 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 31 Aug 2016 GoogleMaps   . Paratypes. SAMC-A090896, Amathole region Stn 3737, Eastern Cape, 32.751° S, 28,415° E, 31 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 23 Feb 2016 GoogleMaps   ; SAMC-A090897, SAMC-A090898, SAMC-A090899, Amathole region Stn 3832, Eastern Cape, 32.759° S, 28.410° E, 45 m, RV Ellen Khuzwayo, collected by R. Payne, dredge, 27 Aug 2016 GoogleMaps   .

Type locality. Amathole region, off East London , Eastern Cape   .

Distribution. Amathole region, off East London, 40.5 m.

Description. Shape varies from either flattened low lying hemispherical (flattened), ranging from 24 mm long by 24 mm wide by 6 mm thick to hemispherical sponges, 13 mm long by 34 mm wide by 27 mm thick ( Fig. 15D View FIGURE 15 ). Surface undulating but smooth, with volcano-shaped oscules, 5 mm high by 3 mm wide at base, 1 mm at apex being closely packed (5mm apart), and a few nodular truncate areolate porefields, 3 mm high by 3 mm wide, with no poral membrane covering the opening. Texture firm, rubbery and tough. Medium to barely compressible, difficult to tear or break. Colour in life either black, dark green/black or dark brown; in preservative dark green ( Fig. 15D View FIGURE 15 ). Green exudate visible, no smell.

Skeleton. The choanosomal skeleton forms an irregular polygonal reticulation formed by wispy tracts of smooth styles ( Fig. 15H View FIGURE 15 ). The tracts range in width from 85 –150 μm in thickness, and form meshes that are 195 μm wide. Within the inner choanosome, tracts diverge towards the surface and are 172–205 μm wide. Interstitial spicules are abundant. The ectosome has a palisade of densely packed interlocking anisodiscorhabds, which are absent from the surface structures. The paratangential layer beneath the palisade is approximately 320 μm deep, and this extends into the oscular fistules.

Spicules. Megascleres are anisostyles in one size category: Large, thick, smooth, straight, occasionally sinuous, centrally thickened, narrow proximal region, fusiform: 696 (480–796) × 18 μm. Microscleres are isospinodiscorhabds I ( Fig. 15E, F View FIGURE 15 ) with 50% of microscleres either having three or two whorls. In some spicules the median whorl is absent or rudimentary. The manubrium is identical to the apical whorl. The median whorl is equidistant from both apical whorl and manubrium, but smaller and shorter: 49 (38–60) μm. Large isospinodiscorhabds II ( Fig. 15G View FIGURE 15 ) with two whorls, 75 (64–88) × 15 (15) μm.

Substratum, depth range and ecology. Occurs off East London, Amathole region at a depth range of 30–42 m.  

DNA sequence data. We sequenced partial COI of collected material from different localities; GenBank accession numbers: COI MK153269 View Materials   MK153271 View Materials   ; MK016476 View Materials   .

Etymology. The species name rethahofmeyri   is given in memory of Emeritus Professor Dr Retha Hofmeyr who joined the Zoology Department at the University of Western Cape in 1974 and served as Head of Department from 1991 to 1992 before she passed away in 2020. Retha will always be cherished and remembered for her kindness and encouragement of her students and staff.

Remarks. Cyclacanthia rethahofmeyri   sp. nov. have acanthose isospinodiscorhabds as microscleres ( Fig. 14 View FIGURE 14 ) and conforms to the general skeletal characteristics of the genus. The examination of this material revealed the presence of a second category of large isospinodiscorhabds ( Fig. 15G, a View FIGURE 15 spicule not present in any other Cyclacanthia   species described to date ( Samaai et al. 2004). The definition of Cyclacanthia   has been expanded to include species with a 2 nd category of isospinorhabds. The COI sequences of the Cyclacanthia   specimens was clearly separated from Tsitsikamma   and formed one, strongly supported phylogenetic cluster characterised by a single distinct haplotype ( Fig. 6 View FIGURE 6 ). Table 7 highlights the morphological characters of the different Cyclacanthia   species and figure 14 shows the different types of isospinodiscorhabds. The family Latrunculiidae   is monophyletic as indicated by the COI phylogeny ( Fig. 6 View FIGURE 6 ).