Leucandra anoducta, Pereira & Azevedo & Hajdu & Cavalcanti & Klautau, 2025

Pereira, Sara Emilly, Azevedo, Fernanda, Hajdu, Eduardo, Cavalcanti, Fernanda F. & Klautau, Michelle, 2025, Calcareous sponges (Porifera, Calcarea) from São Sebastião, São Paulo: new species and new records in two marine protected areas of Southeastern Brazil Ecoregion, Zootaxa 5688 (1), pp. 1-107 : 45-50

publication ID	https://doi.org/10.11646/zootaxa.5688.1.1
publication LSID	lsid:zoobank.org:pub:05E2F9E1-3171-45F3-B0D1-1329D57EFCE6
DOI	https://doi.org/10.5281/zenodo.17017731
persistent identifier	https://treatment.plazi.org/id/03F4630B-FFFC-883E-3EAF-50CB343565DC
treatment provided by	Plazi
scientific name	Leucandra anoducta
status	sp. nov.

Treatment

Leucandra anoducta sp. nov.

urn:lsid:zoobank.org:act:12F1F5DC-2DBB-450D-8038-9C90E484E007

( Figs. 22–25 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 ; Table 11)

Etymology: From “ano-” (without) and “ductus” (Latin for “canal”), referring to the absence of visible choanosomal canals in this species.

Type locality: Celada , São Sebastião Island, Ilhabela, São Paulo State, Brazil .

Type material: Holotype — MNRJ5908 View Materials , Celada , São Sebastião Island, Ilhabela, São Paulo State, Brazil, depth 8 m, coll. E. Hajdu & M. Carvalho, 01/V/2002 . Paratype — MNRJ30123 View Materials , Alcatrazes Archipelago , São Sebastião, São Paulo State, Brazil, depth 12 m, coll. M. Custódio & C. Santos, 03/ V /2002 .

Diagnosis: Leucandra with a lobate massive body and leuconoid aquiferous system, without visible choanosomal canals lined by spicules. The cortical skeleton is formed mainly by small sagittal triactines, while the choanosomal skeleton consists of large regular triactines. Diactines, microdiactines and trichoxeas are also present in the cortex. The atrial skeleton comprises triactines and less abundant tetractines.

Colour: White in life and white or beige in ethanol ( Figs. 22A View FIGURE 22 ; 23A View FIGURE 23 ).

Morphology and anatomy: Massive and lobate body, with one or more oscula without ornamentation, localised on the top of short tubes or as simple openings on the surface of the body ( Figs. 22A, B View FIGURE 22 ; 23A View FIGURE 23 ). The consistency is friable and the texture is rough. The external surface may be slightly hispid, mainly in the tubes bearing oscula ( Fig. 23B View FIGURE 23 ). The hispidation is due to the protruding actines of cortical and choanosomal triactines, as well as diactines, especially in the paratype (MNRJ30123), where diactines are more abundant ( Fig. 23B, C View FIGURE 23 ). The atrium is slightly hispid, as the atrial tetractines project their short apical actines into its lumen. Aquiferous system leuconoid, but choanosomal canals are not evident ( Figs. 22B View FIGURE 22 , 23D View FIGURE 23 ).

The oscular margin is formed by T-shaped triactines and tetractines, in addition to rare, small diactines in the holotype ( Fig. 22C View FIGURE 22 ). The cortical skeleton consists of two categories of triactines: smaller triactines are predominant and form the outer layer, while some larger triactines, identical to the choanosomal ones, are arranged tangentially beneath them, forming an inner layer ( Figs. 22D View FIGURE 22 , 24A View FIGURE 24 ). Diactines, microdiactines and trichoxeas are also present in the cortex, being more abundant in the paratype than in the holotype. Diactines are often concentrated near the oscular region, projecting perpendicularly ( Fig. 23B, C View FIGURE 23 ), while microdiactines and trichoxeas are found scattered, either singly or in tufts ( Figs. 22E, F View FIGURE 22 ; 24A–D View FIGURE 24 ). Despite being more common in the paratype, the microdiactines are not abundant. The choanosomal skeleton is disorganised, comprising large triactines ( Figs. 22B View FIGURE 22 , 23D View FIGURE 23 ). The atrial skeleton is formed predominantly by triactines, but tetractines are also abundant ( Fig. 22G View FIGURE 22 ).

Spicules ( Table 11):

Trichoxeas: Straight or curved, thin and cylindrical ( Fig. 24C View FIGURE 24 ). Often broken. Size:>285.0/2.5 µm.

Diactines: Variable in size. The proximal tip is usually straight and thicker than the distal one, which is slightly curved, a characteristic more evident in the largest diactines. The tips vary from sharp to blunt ( Fig. 25A, B View FIGURE 25 ). Size: 212.0 (±43.1)/8.0 (±2.0) µm.

Cortical microdiactines: Straight or slightly curved, with a sharp proximal tip and a lanceolate distal tip, delimited by a ring-like swelling. Spines are usually present at the distal tip, while the proximal tip is smooth. They are thicker at mid-length or near the proximal end ( Fig. 25C View FIGURE 25 ). Size: 97.2 (±21.3)/4.4 (±1.2) µm.

Small cortical triactines: Sagittal. Actines are straight or subtly undulated, cylindrical to slightly conical, with sharp to blunt tips. The unpaired actine is frequently longer than the paired ones, but highly variable in size ( Fig. 25D View FIGURE 25 ). Size: paired—201.5 (±34.2)/13.4 (±2.0) µm; unpaired—182.0 (±39.1)/12.8 (±2.1) µm.

Large cortical triactines: Identical in shape and size to the choanosomal triactines ( Fig. 22D View FIGURE 22 ). Size: 299.5 (±61.5)/27.6 (±6.9) µm.

Choanosomal triactines: Regular to subregular, with straight, conical, and sharply pointed actines ( Fig. 25E View FIGURE 25 ). Size: 359.5 (±61.6)/33.8 (±7.2) µm.

Atrial triactines and tetractines: Strongly sagittal. Basal actines are cylindrical to slightly conical, with sharp to blunt tips. The unpaired actine is straight and shorter than the paired ones, which are slightly curved ( Fig. 25F View FIGURE 25 ). The apical actine of the tetractines is short, conical, slightly curved, smooth and sharp ( Fig. 25G View FIGURE 25 ). Triactines size: paired—222.8 (±27.1)/13.9 (±2.1) µm; unpaired—148.5 (±39.5)/12.4 (±2.1) µm. Tetractines size: paired—231.5 (±37.7)/13.4 (±2.2) µm; unpaired—145.5 (±54.6)/12.3 (±2.6) µm; apical—53.5 (±9.1)/10.1 (±1.8) µm.

Ecology: The holotype was epibiont on a bivalve and associated with bryozoans and a coral polyp. The paratype was also epibiont on a bivalve, with sediment on its surface, in addition to tubicolous polychaetes, bryozoans and ascidians.

Geographic distribution: Southeastern Brazil ecoregion—São Sebastião Island (Ilhabela) and Alcatrazes Archipelago (São Sebastião), São Paulo State (provisionally endemic), Brazil.

Remarks: The genus Leucandra is noteworthy for its high species richness, comprising 143 valid species ( De Voogd et al. 2025). Nevertheless, L. anoducta sp. nov. is remarkable for the absence of distinguishable choanosomal canals lined by spicules, combined with the presence of cortical diactines and microdiactines. This combination of features is shared only with L. reniformis Tanita, 1942 and L. uschuariensis Tanita, 1942 , both from the southern Chilean and Argetinian coasts, respectively. However, the new species differs from both mainly in the shape and dimensions of its spicules. In both L. reniformis and L. uschuariensis , the cortical and choanosomal skeletons are composed of triactines identical or similar in shape (slightly sagittal) and size, whereas in L. anoducta sp. nov., these spicule categories are quite distinct (cortical triactines are predominantly small and sagittal, while choanosomal triactines are larger and regular). Additionally, the diactines of L. reniformis and L. uschuariensis are more robust (230–420/28–45 µm and 470–700/25–45 µm, respectively) than those of the new species [212.0 (±43.1)/8.0 (±2.0) µm]. Leucandra reniformis has diactines with the distal end thicker than the proximal one, whereas the opposite is observed in the diactines of L. anoducta sp. nov. Furthermore, although cortical and atrial spicules of L. uschuariensis and L. anoducta sp. nov. are corresponding in size, the choanosomal triactines of the new species [359.5 (±61.6)/33.8 (±7.2) µm] are much larger and more robust than those of L. uschuariensis (paired actines: 145–220/18–23 µm, unpaired actine: 120–220/18–23 µm).