Leucandra serrata Azevedo & Klautau, 2007

Lanna, Emilio, Cavalcanti, Fernanda F., Cardoso, Lilian, Muricy, Guilherme & Klautau, Michelle, 2009, Taxonomy of calcareous sponges (Porifera, Calcarea) from Potiguar Basin, NE Brazil, Zootaxa 1973, pp. 1-27 : 16-17

Leucandra serrata Azevedo & Klautau, 2007

Synonyms. Leucandra serrata, Azevedo & Klautau 2007: 11 .

Type material. UFRJPOR 4878 (holotype / ethanol).

Type locality. Angra dos Reis, Rio de Janeiro state, Brazil. (23º40’S – 44º40’W)

Material examined. UFPEPOR 595, Guamaré Harbour, Guamaré, Rio Grande do Norte state (05º06’21.6”S – 36º19’01.6”W), depth: 2 m, coll. G. Muricy, SCUBA, 01/III/2007.

Description. The collected specimen was white alive and in ethanol, and it measures 3.2 x 1.2 x 0.7 cm. It is massive and vasiform (Fig. 7A). Its consistency is hard and slightly compressible. Surface is hispid, rough, and ornamented by giant diactines (Fig. 7B). A single apical osculum surrounded by a crown of trichoxeas is present. Below the osculum there is a large atrium with oval openings of exhalant canals in its walls. The aquiferous system is leuconoid, with spherical choanocyte chambers.

The cortical skeleton is composed of tangentially disposed triactines, large diactines, and rare microdiactines. The large diactines and the microdiactines protrude through the surface. Sometimes, the large diactines cross the entire choanosome, reaching the atrium (Fig. 7C). The choanosomal skeleton is composed of triactines without organisation (Fig. 7B). Tetractines are found surrounding canals and projecting their apical actine into them. The atrial skeleton is composed of sagittal tetractines that project their apical actine into the atrial cavity (Fig. 7D).

Spicules (Table 6). Cortical diactines: fusiform, usually straight but sometimes undulated, and strongly sharp [300.0–822.0 (±340.9)–1,395.0 / 34.5 (±9.7) µm (n = 1 specimen, 15 spicules)] (Fig. 7E). Cortical microdiactines: fusiform, slightly jagged at the tip that protrudes through the surface. Both tips are sharp [63.0–110.2 (±23.0)–154.5 / 2.8 (±0.5) µm (n = 1 specimen, 30 spicules)] (Fig. 7F). Cortical triactines: subregular, with actines of different sizes. These actines are conical and sharp [paired actines: 135.0–223.3 (±43.7)–306.0 / 9.8 (±2.2) µm (n = 1 specimen, 30 spicules)], [unpaired actine: 60.0–190.2 (±84.4)–375.0 / 10.1 (±2.1) µm (n = 1 specimen, 30 spicules)] (Fig. 7G). Choanosomal triactines: sub-regular with the unpaired actine longer than the paired ones. Actines are cylindrical and sharp [paired actines: 156.0–294.0 (±63.9)–426.0 / 26.8 (±6.0) µm (n = 1 specimen, 30 spicules)], [unpaired actine: 78.0–193.2 (±63.0)–390.0 / 28.4 (±5.9) µm (n = 1 specimen, 30 spicules)] (Fig. 7H). Tetractines of canals: Sagittal. Paired actines are slightly larger than the unpaired one. Basal actines are cylindrical with sharp ends (Fig. 7I). The apical actine is sharp [paired actines: 90.0–164.3 (±32.2)–213.0 / 9.8 (±2.1) µm (n = 1 specimen, 30 spicules)], [unpaired actine: 75.0–136.0 (±41.5)–240.0 / 11.2 (±2.1) µm (n = 1 specimen, 30 spicules)], [apical actine: 30.0–46.2 (±13.9)–75.0 / 7.2 (±2.0) µm (n = 1 specimen, 12 spicules)]. Atrial tetractines: sagittal. Paired actines are larger than the unpaired one. Basal actines are cylindrical, with sharp tips. The apical actine is shorter than the basal ones, conical, sharp, and smooth [paired actines: 90.0–148.8 (±34.8)–198.0 / 7.4 (±2.0) µm (n = 1 specimen, 13 spicules)], [unpaired actine: 45.0–60.5 (±16.6)–129.0 / 6.2 (±1.0) µm (n = 1 specimen, 30 spicules)], [apical actine: 18.0–30.0 (±17.0)–42.0 / 3.7 (±3.2) µm (n = 1 specimen, 2 spicules)] (Fig. 7J).

TABLE 6. Spicule measurements of Leucandra serrata (UFPEPOR 595) (individual actines, in Μm); s, standard deviation.

Spicules Actines Length Width n

Min Mean s Max Mean s Known distribution. Endemic from Brazil: Angra dos Reis (Rio de Janeiro state; Azevedo & Klautau 2007). First record from Rio Grande do Norte state.

Ecology. In Potiguar Basin, Leucandra serrata was found in a harbour environment, subjected to high sedimentation. Photophilous.

Remarks. Leucandra serrata was originally described from Angra dos Reis, Rio de Janeiro state, in SE Brazil ( Azevedo & Klautau 2007). The presence of jagged microdiactines was conclusive to identify it as L. serrata , although spicules of the specimen from Potiguar Basin are a little shorter than those from Rio de Janeiro ( Azevedo & Klautau 2007)