Aplysina muricyana, Pinheiro, Ulisses Dos S., Hajdu, Eduardo & Custódio, Márcio R., 2007

Pinheiro, Ulisses Dos S., Hajdu, Eduardo & Custódio, Márcio R., 2007, Aplysina Nardo (Porifera, Verongida, Aplysinidae) from the Brazilian coast with description of eight new species, Zootaxa 1609, pp. 1-51 : 36-39

Aplysina muricyana sp.n. ( Fig. 16 D, 17C–F, 20, Tab. X)

Aplysina sp. sensu Neves & Omena (2003)

Holotype: MNRJ 6196, Laguna (Reserva Biológica do Atol das Rocas, RN) E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 25/VIII/2002.

Paratypes: Reserva Biológica do Atol das Rocas (RN) - MNRJ 2139, Salão (ca. 03º52'52'' S – 33º48'51'' W), 4 m depth, G. Muricy coll., 28/II/1999. MNRJ 2168, Piscina do Barretão, 3 m depth, F. Moraes coll., 01/ III/1999. MNRJ 2173, Fenda (03º51'18.6'' S – 33º47'52.1'' W), G. Muricy coll., 02/III/1999. MNRJ 6195, Laguna, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 21/VIII/2002. MNRJ 6197, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 24/VIII/2002. MNRJ 6198, Laguna, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 21/ VIII/2002. MNRJ 6199, Salão, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 30/VIII/2002. MNRJ 6200– 6202, Fenda (03º51'20.1'' S – 33º47'50.2'' W), E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 25/VIII/2002, voucher. MNRJ 6203–6204, Piscina das Rocas, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 24/VIII/2002. MNRJ 6205, Laguna, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 25/VIII/2002. MNRJ 6301, Piscina das Rocas, E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 24/VIII/2002. MNRJ 6364, Fenda (03º51'20.1'' S – 33º47'50.2'' W), E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 27/VIII/2002. MNRJ 6663, Piscina das Âncoras (03º52'31.5'' S – 33º48'20.8'' W), E. Hajdu, M.V. Oliveira and U. Pinheiro coll., 31/VIII/2002.

Additional material: Reserva Biológica do Atol das Rocas (RN) - MNRJ 4493, 4494, Salão (ca. 03º52'52'' S – 33º48'51'' W), G. Neves coll., XI/1999. MNRJ 4502, Fenda, G. Neves coll., XI/1999.

Diagnosis: Irregular polygonal tubes, laterally anastomosed, predominantly beige in vivo. Colour ranging from bright pale-yellow to dark reddish-brown.

Description of the species:

Specimens are composed of laterally anastomosed tubes with an irregular polygonal outline, in creeping groups of up to 45 tubes, with clusters having a maximum of 36 cm in length and 3 cm in width. The polygonal outline results from discrete edges extending upwards from the base of the sponge on its free sides ( Figs. 17 C–F, 20A–B). Some short tubes are projected from the base in varied directions. The surface is finely conulose. The sponge possesses large pseudoscula, frequently apical or pseudo-apical (eccentric), varying from 0.5 cm to 1 cm in diameter, small oscula on the tubes’ outer sides being also visible. In specimen MNRJ 2139, oscula have an iris-type diaphragm. The predominant colour in vivo is beige, specimens with green, brown, brownish-beige and red tinges being also common. After preservation in ethanol specimens vary from beige to brown. Consistency is soft.

Skeleton: Choanosome with a delicate and irregular network of spongin fibers ( Figs. 20C–D ) with amber colour bark 38–126 Μm thick (average 72 Μm) and a thick pith that can be black or amber 8 to 50 Μm (average 29 Μm; Fig. 20E ). The presence of spongin fibers wrapped and excavated by filamentous structures, possibly fungi, was observed in some specimens as in Aplysina pseudolacunosa sp.n.

TABLE X: Spongin fibres’ measurement data for Aplysina muricyana sp.n. (in micrometers; S.D. = Standard Deviation and N=30).

Specimens Locality* Fibers Piths

Thinnest Mean Thickest S.D. Thin- Mean Thickest S.D. nest

Holotype Atol das Rocas, RN 51.3 75.2 117.3 12.3 11.3 17.4 27.6 3.4

MNRJ 6196

Paratype Atol das Rocas, RN 50.0 84.2 126.3 18.6 12.5 16.4 22.5 3.0

MNRJ 2139

Paratype Atol das Rocas, RN 52.5 73.8 91.3 9.0 12.5 19.3 28.8 3.8

MNRJ 2168

Paratype Atol das Rocas, RN 41.3 74.5 105.0 16.7 10.0 14.9 28.8 4.1

MNRJ 2173

MNRJ 4493 Atol das Rocas, RN 42.5 65.3 83.8 9.8 12.5 18.2 25.0 4.2 Distribution: Provisionally known only from the type locality, Atol das Rocas (RN, Brazil; Fig. 16 D).

Ecology: All specimens were collected in shallow-waters at Atol das Rocas, inside large crevices, and the species is thus considered to be sciaphilous. Inside the atoll, depth of occurrence was limited to 5 m, but outside the atoll ring, specimens were seen down to 15 m. Specimens in darker areas were completely beige, and those more exposed to light, more intensely pigmented with darker colours, as a likely consequence of association with cyanobacteria.

Etymology: The name of the species honours Dr. Guilherme Muricy, for his pioneering studies on the taxonomy of Atol das Rocas sponges, who also collected many of the specimens studied here.

Remarks: The species which appear closest to A. muricyana sp.n are A. insularis and A. pseudolacunosa sp.n. described below. Another similar species is A. fistularis , which presents tubes of distinct morphology, never forming the large, frequently creeping clusters so frequently observed in the new species. Tubes in A. fistularis , albeit varied as regards length, as well as number and size of projections, were never seen to have a polygonal cross section. The possibility that A. muricyana sp.n. could be nothing but an ecomorph of a well established species appears quite unlikely, as dives performed on the outer ring of Atol das Rocas, down to 15m depth, failed to reveal any additional Aplysina species. Rather, the same A. muricyana sp.n. was present inside somewhat deeper crevices (10–15 m depth). Another species which also presents anastomosed tubes is A. insularis . However, A. insularis has soft and stout tubes, with yellow or brown colour in vivo turning black after preservation. In contrast, A. muricyana sp.n. has hard, much less stouter polygonal tubes, with variable colour in vivo and brown or beige colour after preservation. Comparison with A. pseudolacunosa sp.n. will be provided below.

Figures

FIGURE 16: Map showing the distribution of Aplysina along the Brazilian coastline. A. Aplysina cristagallus sp. n .. B. Aplysina lactuca sp. n .. C. Aplysina lingua sp. n.. D. Aplysina muricyana sp. n .. Scale bar = 500 km.

FIGURE 17: A. Aplysina lactuca sp. n. in situ, Holotype – MNRJ 5477 (Parque Nacional Marinho dos Abrolhos, BA, Brazil). B. Aplysina lingua in situ, Paratype—MNRJ 5469 (Parque Nacional Marinho dos Abrolhos, BA, Brazil). C – F. Aplysina muricyana in situ, Reserva Biológica do Atol das Rocas, (RN, Brazil). Scale bar = 1 cm.

FIGURE 20: A – E. Aplysina muricyana sp. n. Holotype (MNRJ 6196). A – B. habit after preservation. C – D. Skeletal architecture. E. Spongin fibres. Scale bars = A – B. 1 cm, C – D. 500 µm, E. 50 µm.