Auletta akaroa, Cavalcanti & Recinos & Pinheiro, 2017

Cavalcanti, Thaynã, Recinos, Radharanne & Pinheiro, Ulisses, 2017, Two new Auletta Schmidt, 1870 (Axinellidae; Demospongiae; Porifera) from Brazil, Zootaxa 4273 (1), pp. 121-130 : 122-124

Auletta akaroa sp. nov.

( Figures 1–3 , Table 1)

Type locality: Brazil, Alagoas State, off Coruripe Municipality.

Type specimens: Holotype. UFPEPOR 3054, off Coruripe Municipality (10°02’45’’S – 35°43’00’’ W), Alagoas State, Brazil, depth 90 m, st. 73E, coll. Akaroa expedition (5/IX/1965).

Diagnosis. Auletta akaroa sp. nov. is a stalked tubular sponge, megascleres are small and sinuous: styles (280– 383 / 3–6 µm, length / width) and strongyles (228–386 / 6–8 µm, length / width).

External morphology ( Fig. 2 A–C). Stalked tubular sponge with 5.0 x 0.6 cm (length x width). Cluster of four tubes over a single base, two of them are completely laterally anastomosing, the other are in anastomosing next to base. Tubes have irregular shape with soft constrictions. All tubes have one apical osculum, but only one tube presents a single lateral osculum. The oscula are 3–4 mm (diameter). Surface is smooth and consistency is compressible and flexible. Colour is reddish-brown when preserved (ethanol 80%), colour in life is unknown.

Skeleton ( Fig. 2 D–F). No special ectosomal skeleton. Abundant spongin bearing the surface. Coanosomal skeleton plumoreticulate with multispicular tracts of strongyles connected by tracts of uni- or paucispicular styles.

Spicules ( Fig. 3 A–D). Styles (280–325.7–383 / 3–4.7–6 µm, length / width): smooth, straight to slightly sinuous, rounded tips on some with subterminal knobs ( Fig. 3 A, C); Strongyles (228–322.0–386 / 6–6.5–8 µm, length / width): smooth, slightly curved to sinuous, strongyloxeas forms are present ( Fig. 3 A, D).

Distribution and ecology. Known only from the type locality: off Coruripe Municipality (Alagoas State, Northeastern Region, Brazil), in 90 m depth. The specimen was collected on muddy and gravel substrate.

Etymology. The species name honors the Akaroa Project, expedition undertaken by the fishing boat Akaroa , which collected sponges along Alagoas and Sergipe States ( Brazil).

Remarks. Auletta akaroa sp. nov. is a typical Auletta by its external morphology, spicule complement, presence of plumoreticulate skeleton, sinuous strongyles, styles and tubular shape. The most similar species is A. sycinularia which shares styles and strongyles with similar features, but A. sycinularia presents two categories of styles and larger strongyles than the new species ( Table 1). Auletta akaroa sp. nov. also differs from A. tuberosa due to the presence of the spicule complement of styles, oxeas and strongyles, and presence of prominent tubercles on its tubes. The new species differs from A. andamanensis Pattanayak, 2006 , A. aurantiaca Dendy, 1889 , and A. lyrata (Esper, 1794) by their absence of strongyles. Presence of oxeas are characteristics of the species A. consimilis Thiele, 1898 , A. dendrophora Wilson, 1904 , A. elongata Dendy, 1905 , A. halichondrioides Thiele, 1898 , A. krautteri Austin et al, 2013 . Auletta akaroa sp. nov. differs from the North Atlantic species A. grantioides , A. pedunculata and A. sessilis because they have much larger styles and strongyles ( Table 1). Finally, the new species differs from A. tubulosa by it spicules complement of only two categories of styles.

Figures

FIGURE 1. Location of the studied area and the collection sites of Auletta species: (1) Auletta akaroa sp. nov. (Alagoas State); (2), (3) Auletta laboreli sp. nov. (Pernambuco State).

FIGURE 2. Auletta akaroa sp. nov. (UFPEPOR 3054, holotype). A, specimen preserved; B – C, details of oscula; D, thick section showing the ectosome and choanosome; E, detail of multispicular tracts of strongyles; F, detail of uni- and paucispicular styles. Scale bars: A = 1 cm; B – C = 5 mm; D – E = 150 µm.

FIGURE 3. Spicule complement of Auletta akaroa sp. nov. in SEM (UFPEPOR 3054, holotype). A, size variation of styles; B, strongyles; C, tips of styles; D, details of strongyles. Scale bars: A – B = 100 µm; C = 20 µm; D = 10 µm.