Paraleucilla incomposita Cavalcanti, Menegola & Lanna, 2014

Chagas, Cléslei & Cavalcanti, Fernanda F., 2017, Taxonomy of calcareous sponges (Porifera, Calcarea) sampled on artificial substrates of a recreational marina in the Tropical Northeastern Brazilian coast, Zootaxa 4363 (2), pp. 203-224 : 208-213

Paraleucilla incomposita Cavalcanti, Menegola & Lanna, 2014

Synonymies. Paraleucilla incomposita: Cavalcanti et al. 2014: 547 .

Type material. UFBA 4246 - POR. [Holotype. Martim Pescador Reef , Arraial d’Ajuda (1629’S 3903’W), Bahia, Brazil; 14/V/2012; 3 m depth; collected by Romário Guedes] .

Type locality. Arraial d’Ajuda , Bahia, Brazil.

Analysed material. UFBA 4532 - POR and UFBA 4533 - POR [Marina of the Nautical Tourist Terminal of Bahia (1258’20.8’’S, 3830’54.6’’W), Salvador, Bahia State , Brazil; collected by C. Chagas; 20/II/2016; 1 m depth] , UFBA 4560 - POR (same locality and collector; 10/XI/2016; 0.5 m depth) , UFBA 4669 - POR (same locality and collector; 22/X/2016; 1 m depth), and holotype .

Description: Colour is beige alive and after fixation. The largest specimen measures 1.6 x 0.75 cm (height x width). It has a hispid surface and an ovoid shape with a single apical osculum surrounded by a short fringe of trichoxeas ( Figures 4A ). The atrial cavity is wide, and the atrium is hispid due to the apical actines of tetractines. The body wall is 0.2 cm thick. The aquiferous system is leuconoid, with oval choanocyte chambers.

The specimens UFBA 4533-POR and UFBA 4560-POR have subcortical lacunae and a thick layer free of choanocyte chambers just below the cortex ( Figures 4B,C ). The cortical skeleton is formed by tetractines with curved basal actines and the apical one facing the choanosome ( Figures 4B–D ). Tangential triactines are also present, but they are not equally distributed on the sponge surface. Thus, these triactines are not found in some of the skeletal sections, although they are common in other sections of the same specimen ( Figure 4B ). Trichoxeas and giant diactines penetrate the cortex ( Figures 4B–D ). The inarticulated skeleton is formed by the apical actines of cortical tetractines and the unpaired actine of several subatrial tetractines and few subatrial triactines ( Figures 4B–D ). Thickness of the inner region varies among the specimens. Spicules are present in disarray in this inner region, with the exception of the subatrial tetractines II that are organised around canals ( Figures 4E , 5F ). Rare thin tetractines with a long unpaired actine extending to the choanosome were observed close to the atrial wall. The atrial skeleton is formed exclusively by tangential tetractines with a long apical actine projected to the atrium ( Figure 4F ). These spicules are thinner than the other tetractines of the skeleton. A remarkable feature of this species is the occurrence of very rare choanosomal pentactines. Only one broken pentactine was found in the preparations containing skeletal sections (UFBA 4532-POR), but additional pentactines were found in the slides of dissociated spicules of the specimens UFBA 4532-POR and UFBA 4560-POR ( Figure 5I ).

Spicules Actines Length (µm) Width (µm) N

Min. Mean SD Max. Mean SD Diactines

UFBA 4532 308.0 893.2 336.2 1558.0 32.0 7.7 30 UFBA 4669 232.1 1096.0 279.8 1649.0 36.3 5.7 30 Cortical tetractines

UFBA 4532 Paired 105.0 191.3 34.9 236.3 15.5 2.5 28 UFBA 4669 141.6 208.1 28.8 266.6 14.3 3.1 30 UFBA 4532 Unpaired 46.5 112.6 37.1 182.0 9.5 3.3 22 UFBA 4669 111.7 187.2 28.9 230.0 18.2 2.5 28 UFBA 4532 Apical 100.9 202.1 9.8 216.6 17.1 2.9 26 UFBA 4669 121.1 210.7 23.0 250.0 16.8 3.2 26 Cortical triactines

UFBA 4532 Paired 65.3 141.0 42.4 214.6 8.7 2.4 22 UFBA 4669 117.1 209.1 40.6 273.5 6.6 1.3 23 UFBA 4532 Unpaired 46.5 119.2 38.9 197.1 8.5 2.9 22 UFBA 4669 104.1 172.8 48.0 277.6 7.5 1.5 23 Subatrial triactines

UFBA 4532 Paired 75.6 175.5 45.7 308.2 10.5 3.0 30 UFBA 4669 163.5 210.3 36.8 310.0 10.7 3.0 29 UFBA 4532 Unpaired 63.6 138.9 45.5 263.8 11.4 4.0 30 UFBA 4669 104.7 168.8 47.9 277.9 11.7 3.7 29 Subatrial tetractines I

UFBA 4532 Paired 140.9 242.0 40.0 324.8 17.6 2.8 30 UFBA 4669 169.3 258.5 35.0 323.4 20.0 3.2 30 UFBA 4532 Unpaired 159.0 241.1 48.1 337.6 19.0 2.5 30 UFBA 4669 142.2 242.6 57.5 367.2 21.7 3.1 30 UFBA 4532 Apical 17.0 45.3 22.8 136.5 15.1 3.0 30 UFBA 4669 32.0 70.3 31.6 175.7 17.9 4.1 30 Subatrial tetractines II

UFBA 4532 Paired 115.4 186.5 55.2 285.4 16.8 3.0 18 UFBA 4669 172.5 235.2 33.7 285.2 18.7 4.2 14 UFBA 4532 Unpaired 123.9 190.7 41.8 245.0 14.7 7.2 18 UFBA 4669 107.4 214.7 42.8 269.9 16.3 2.9 14 ......continued on the next page Spicules Actines Length (µm) Width (µm) N

Min. Mean SD Max. Mean SD Spicules ( Table 2; measurements obtained from two specimens):

Trichoxeas: They are very thin and long, most of them are broken.

Diactines: They are fusiform, slightly curved and sharp or with one of the tips blunt and the other arrow-shaped [232.1– 1018.6 (322.8)–1649.0/12.1– 34.6 (6.9)–46.3µm; Figure 5A ].

Cortical triactines: Actines are cylindrical to slightly conical and blunt. The paired actines are commonly curved. Size is variable [paired: 65.3– 175.8 (53.9)–273.5/3.7– 7.6 (2.1)–15.0 µm; unpaired: 46.5– 146.6 (51.9)– 277.6/4.8– 8.0 (2.3)–14.9 µm; Figure 5B ].

Cortical tetractines: Slightly conical with sharp tips. The paired actines are slightly curved while the unpaired one is long and straight. The apical actine is short or is the same size as the unpaired actine [paired: 105.3– 193.7 (35.4)–266.6/9.3– 15.6 (3.1)–31.3 µm; unpaired: 46.5– 154.4 (49.5)–230.0/5.3– 14.4 (5.2)–25.4 µm; apical: 101.0– 206.4 (34.3)– 266.7/11.0– 16.9 (2.7)–23.4 µm; Figure 5C ].

Subatrial tetractines I: They are slightly conical, with sharp tips and of variable size. The unpaired actine is the same size or larger than the paired ones. Apical is long and slightly curved. Sometimes the apical actine is displaced and does not originate from the exact point as the base of the other actines [paired: 140.9– 250.3 (38.2)– 324.8/13.2– 18.8 (3.2)–26.5 µm; unpaired: 142.2– 241.9 (52.6)–367.2/14.0– 20.4 (3.1)–28.1 µm; apical: 17.0– 57.8 (30.1)–175.7/8.7– 16.5 (3.8)–27.7 µm; Figures 5D , D’].

Subatrial triactines: Slightly conical and blunt. The paired actines are larger than the unpaired and sometimes they are curved. The unpaired actine is straight [paired: 75.6– 192.6 (44.8)–309.9/5.3– 10.6 (3.0)–18.1 µm; unpaired: 63.7– 153.7 (48.7)–277.9/6.1– 11.6 (3.6)–22.9 µm; Figure 5E ].

Subatrial tetractines II (around the canals): Slightly conical and smaller than the tetractines of the choanosome. Blunt tips. The unpaired actine is shorter or the same size as the paired actines. Apical is short, curved and sharp [paired: 115.5– 210.9 (51.3)–285.2/12.0– 17.6 (3.8)–31.3 µm; unpaired: 107.4– 202.7 (43.3)–268.9/5.3– 15.5 (5.5)– 28.0 µm; apical: 3.0– 11.7 (5.6)–25.6/1.3– 4.9 (1.9)–10.0 µm; Figure 5F ].

Thin tetractines (close to the atrial wall): Cylindrical and blunt. Paired actines may be curved while the unpaired one is straight and larger, extending to the choanosome. The apical actine is short [paired: 193.9– 272.2 (63.3)–385.4/7.3– 15.3 (4.8)–24.4 µm; unpaired: 299.4– 405.3 (77.3)–533.1/8.0– 13.8 (3.2)–19.4 µm; apical: 34.1– 50.5 (8.3)–72.9/3.5– 7.5 (2.4)–11.1 µm; Figure 5G ].

Atrial tetractines: Cylindrical with sharp tips. The paired actines are curved, while the apical actine is straight and shorter than the paired actines, but larger than the apical of the other tetractines of the skeleton. The unpaired actine is slightly curved and small or is the same size as the paired actines ( Figures 5H , H’). Commonly, the base of the apical actine is displaced and does not originate from the exact point as the base of the other actines [paired: 94.7– 149.7 (30.2)–223.0/4.1– 10.1 (4.0)–20.0 µm; unpaired: 55.1– 111.7 (19.4)–141.6/6.1– 10.7 (2.7)–17.7 µm; apical: 45.1– 101.0 (24.5)–141.0/4.3– 7.7 (1.9)–11.6 µm; Figure 5H ].

Choanosomal pentactines: Slightly conical with sharp tips. Size and shape are variable. The basal system may consist of two large paired actines and two small paired actines. The apical actine is short and curved [shortest paired: 59.5– 109.6 (49.8)–167.0/6.8– 9.8 (3.7)–14.9 µm; largest paired: 64.3– 138.8 (65.2)–210.5/6.3– 10.9 (4.2)– 16.0 µm; apical: 17.1– 36.1 (16.2)–51.2/3.6– 9.9 (5.3)–15.0 µm; Figure 5I ).

Ecology. Most of the specimens were found on nautical cables that remained submerged in the studied area for 2 months. So, this is the maximum age of the individuals. The only exception is UFBA 4560-POR, sampled on a nautical cable used to dock a boat. Embryos were observed in the specimens UFBA 4532-POR and UFBA 4533- POR collected in February 2016 ( Figure 4B ). Beyond the calcareous sponges, we also found tunicates, demosponges, bryozoans and macroalgae on the cables that were intentionally submerged.

Bathymetric data for P. incomposita were limited to the holotype, found at a 3 m depth ( Cavalcanti et al. 2014). The specimens described here were sampled at 0.5 or 1 m depths.

Remarks. Recently, Lanna et al. (2017) showed that the diagnostic character used to differentiate Leucilla Haeckel, 1872 and Paraleucilla varies according to the volume and body wall thickness. Thus, differences between those genera are unclear. Until a systematic revision can be provided, we followed current classification and allocated the specimens in the genus Paraleucilla .

Paraleucilla incomposita was recently described at the southern coast of Bahia, ca. 400 km away from the study area. The specimens analysed here presented two features that make them slightly different from the content of the original description of P. incomposita : the presence of rare pentactines and the shape of some tetractines that have a displaced apical actine. Nevertheless, after analysing the holotype of this species (UFBA 4246-POR), we concluded that both features had been overlooked by the authors ( Figures 5J, K ). Only one pentactine was found in the holotype, showing that, as in the other specimens, it is very rare and thus should not be considered as a diagnostic character of P. incomposita . To date, pentactines had previously been observed only in Sycon pentactinale Rossi, Farina, Borojevic & Klautau, 2006 , and P. incomposita is the second species of calcareous sponges with this type of spicule in its skeleton. Similar to some of the specimens described here, the holotype of P. incomposita also exhibits subcortical lacunae.

Figures

FIGURE 4. Paraleucilla incomposita (UFBA 4532-POR, except for B, C, and D—UFBA 4533-POR). A—Preserved specimenand oscular fringe (in detail);B—Cross section showingthe layer withsubcortical lacunae (*) and free ofchoanocyte chambers (black line). Embryos (arrow) can be observed; C—Longitudinal section with a general view of the skeletal organisation from the cortical (cx) to the atrial (at) regions; D—Detail of the outer region (OR) and inner region below that; E—Crosssection showing a choanosomalcanal (cc) with apical actines of tetractines close to the atrium (at); F—Cross section of the atrium (at) with apical actines of tetractines protruding into it.

FIGURE 5. Paraleucilla incomposita (A–I: UFBA 4532-POR. J, K: UFBA 4246-POR holotype). A—Diactine; B—Cortical triactine; C—Cortical tetractine; D, D’—Subatrial tetractines I; E—Subatrial triactine; F—Subatrial tetractines II; G—Thin subatrial tetractine;H, H’—Atrial tetractines; I—Pentactine; J—Pentactineof the holotype; K—Tetractine of the holotype with displaced apical actine.