Aplysina lactuca, 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 : 33-35

Aplysina lactuca sp.n. ( Figs. 16 B, 17A, 18, Tab. VIII)

Holotype: MNRJ 5477, Siriba Island, (Parque Nacional Marinho dos Abrolhos, BA), 10 m depth, U.S. Pinheiro and E. Esteves coll., 02/III/2002.

Paratypes: MNRJ 5276, 5278, Pedra do Silva, south side, (Reserva Extrativista de Corumbau, Prado, BA, 16º53'42.1'' S - 39º05'31.2'' W), 5 m depth, U.S. Pinheiro coll., 23/I/2002.

Additional material: MNRJ 8672, Parque Estadual da Pedra da Risca do Meio (03°35'889 S - 38°23'481 W, Fortaleza, CE, Brazil), 22 m depth, E. Hajdu coll., 14/VII/2004.

Diagnosis: It presents a centrally anastomosed lamellar form, which reminds the root buttresses of large tropical canopy trees. The species is yellowish-brown in vivo, turning purple after preservation in ethanol.

Description of the species:

The specimens besrs centrally anastomosed lamellas, giving the sponge a form which reminds the root buttresses of large tropical canopy trees ( Figs. 17A , 18A–B ). Some lamellas possess ridges and holes longitudinaly extending themselves from the base to the top, in only one of the sides. Small oscula (0.1 cm wide) are spread on all sides. The surface is finely conulose, with small depressions. The colour is yellowish-brown in vivo, turning purple after preservation in ethanol. Consistency is very soft and flexible.

Skeleton: Choanosome with a delicate and irregular network of spongin fibers ( Fig. 18C ). Bark with amber colour and thickness of 37–155 Μm (average 74 Μm). Thick pith can be black or amber with thickness of 7 –35 Μm (average 19 Μm; Fig. 18D ).

Distribution: Provisionally endemic from the northeastern Brazilian coast ( Fig. 16 B). The type locality is the Abrolhos region, located in the southern limit of the northeastern Brazilian sector.

Ecology: The four collected specimens were photophilous, and always found on the upper part of rocks or coral heads. They were collected in depths that varied from 5 to 22 m.

Etymology: The name of this species is related to its resemblance to a lettuce ( lactuca in Latin). Remarks: Other species which bear some resemblance to A. lactuca sp.n. are A. alcicornis sp.n., A. cristagallus sp.n. and A. solangeae sp.n. However, although they all possess a lamellar form, none of them have centrally anastomosed lamellas as seen in A. lactuca sp.n.

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

Specimens Locality* Fibers Piths

Thinnest Mean Thickest S.D. Thinnest Mean Thickest S.D.

Holotype Abrolhos, BA 62.5 90.3 155.0 18.6 7.5 18.2 35.0 5.7

MNRJ 5477

Paratype Corumbau, BA 37.5 63.2 75.0 9.8 15.0 25.3 35.0 4.8

MNRJ 5276

Paratype Corumbau, BA 55.0 69.3 90.0 8.4 15.0 24.7 35.0 6.6

MNRJ 5278

* BA, Bahia State.

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 18: A – D. Aplysina lactuca sp. n. Holotype (MNRJ 5477). A – B. habit after preservation. C. Skeletal architecture. D. Spongin fibres. Scale bars = A – B. 5 cm, C. 500 µm, D. 50 µm.