Arthuria undetermined

Azevedo, Fernanda, Cóndor-Luján, Báslavi, Willenz, Philippe, Hajdu, Eduardo, Hooker, Yuri & Klautau, Michelle, 2015, Integrative taxonomy of calcareous sponges (subclass Calcinea) from the Peruvian coast: morphology, molecules, and biogeography, Zoological Journal of the Linnean Society 173 (4), pp. 787-817: 793-796

publication ID

http://doi.org/ 10.1111/zoj.12213

persistent identifier

http://treatment.plazi.org/id/03C387F7-FFD5-2752-CEA7-99C6CE111BC9

treatment provided by

Carolina

scientific name

Arthuria undetermined
status

SP.

ARTHURIA SPIRALLATA SP.   NOV. ( FIGS 2 View Figure 2 , 3 View Figure 3 ; TABLE 3)

Type material: Holotype (ethanol). MNRJ 11414 View Materials – fragments from the holotype: RBINSc-IG 32239- POR 11414, CZA 11414, and MHNG 85411 View Materials   . Paratypes (ethanol). MNRJ 11397 View Materials – fragments from the paratype: RBINSc- IG 32239- POR 11397, CZA 11397   and MHNG 85395 View Materials . MNRJ 12860 View Materials – fragment from the paratype: RBINSc- IG 32240- POR 12860 and CZA 12860   . MNRJ 16745 View Materials – fragment from the paratype: RBINSc-IG 32239- POR 16745 View Materials   .

Material examined: Six specimens. MNRJ 11397 View Materials ; San Cristobal, Lobos de Afuera Islands , Guano Islands and Capes National Reserve System (06°54′52.50′′S, 80°42′55.90′′W); collected by Ph. Willenz and Y. Hooker; 13 m depth; 07.x.2007 GoogleMaps   . MNRJ 11414 View Materials ; San José Inlet , Lobos de Afuera Islands , Guano Islands, and Capes National Reserve System (06°55′48.50′′S, 80°43′16.20′′W); collected by Y. Hooker; 9 m depth; 09.x.2007 GoogleMaps   . MNRJ 12860 View Materials ,   MNRJ 12864 View Materials ; Roquedal , Laguna Grande , Paracas National Reserve, Ica Region (14°09′11.80′′S, 76°15′01.30′′W); collected by Y. Hooker and Ph. Willenz; 1–2 m depth; 12.xii.2008 GoogleMaps   . MNRJ 13652 View Materials ; Sechura Bay site 4, Parachique, Piura Region (05°44′24.10′′S, 80°57′05.60′′W); collected by Y. Hooker and Ph. Willenz; 19 m depth; 07.xii.2009 GoogleMaps   . MNRJ 16745 View Materials ; El Lagarto Islet , Lobos de Afuera Islands , Guano Islands, and Capes National Reserve System (06°56′01.20′′S, 80°42′19.90′′W); collected by E. Hajdu; 12 m depth; 04.x.2007 GoogleMaps   .

Type locality: San José Inlet , Lobos de Afuera Islands , Guano Islands , and Capes National Reserve System, Peru   .

Colour: Opaque white or translucent light beige in life and beige in ethanol.

Etymology: Named from the Latin spira, meaning spiral. Refers to the shape of the apical actine of most tetractines.

Description: Sponge thickly encrusting or massive (3.0 × 1.5 × 0.8 cm) ( Figs 2A–C View Figure 2 , 3A–C View Figure 3 ). The massive forms are frequently spherical. Consistency is compressible. Cormus is formed by irregular and frequently tightly anastomosed tubes (0.5−1.0 mm). Water-collecting tubes are present, but in some specimens there is only a single osculum. Granular cells were not observed. Aquiferous system is asconoid.

Skeleton: Without any special organization. It is composed of three size categories of triactines and one size category of tetractines; however, tetractines are very rare ( Figs 2D View Figure 2 , 3D View Figure 3 ). Size categories of tetractines are in the same range as triactines.

Spicules ( Table 3):

1. Triactines I (large): regular (equiangular and equiradiate). Actines are conical or slightly conical, depending on the specimen, and have sharp tips ( Figs 2E, F View Figure 2 , 3E–G View Figure 3 ). They are found mainly outside the tubes.

2. Triactines II (intermediate): regular (equiangular and equiradiate) or sagittal.Actines are slightly conical with sharp tips ( Figs 2G, H View Figure 2 , 3H, I View Figure 3 ). This is the most frequent type of spicule. Size highly variable.

3. Triactines III (small): regular (equiangular and equiradiate). Actines are conical with sharp tips. Size highly variable ( Figs 2I, J View Figure 2 , 3L, M View Figure 3 ).

4. Tetractines: very rare. Size highly variable ( Figs 2K, L View Figure 2 , 3J, K View Figure 3 ). Apical actines are frequently spiralled, but straight forms also occur ( Fig. 2M, N View Figure 2 ).

Reproduction: Unknown

Ecology: This species lives in habitats with moderate to high amounts of sediment. A reasonable quantity of fine sediment was found amongst tubes of the cormus of the holotype specimen ( MNRJ 11414). Some individuals were growing on gastropod shells ( Crepidula sp.   ) and others underneath boulders, near polychaete reefs. Specimens were found sharing the substrate with bryozoans, lophophorates, and serpulid polychaetes as well as some other calcareous sponges ( Soleneiscus pedicellatus   sp. nov. and Leucosolenia sp.   ). Some polychaetes occurred amongst the tubes of the cormus of specimen MNRJ 12860. Known bathymetrical distribution extends from 1 to 13 m depth.

Geographical distribution: North (5°S) and south coasts of Peru (14°S) ( Fig. 3N View Figure 3 )   .

Remarks: The genus Arthuria   was recently proposed ( Klautau et al., 2013). It comprises eight species: Arthuria africana ( Klautau & Valentine, 2003)   ( South Africa), Arthuria alcatraziensis ( Lanna et al., 2007)   ( Brazil), Arthuria canariensis ( Miklucho-Maclay, 1868)   (Gulf of Mexico, Azores, Canary and Madeira Islands, Adriatic Sea and European waters), Arthuria dubia ( Dendy, 1891)   ( Australia), Arthuria hirsuta ( Klautau & Valentine, 2003)   ( South Africa), Arthuria passionensis ( van Soest, Kaiser & van Syoc, 2011)   ( Clipperton Island), Arthuria sueziana ( Klautau & Valentine, 2003) (Red Sea)   , and Arthuria tenuipilosa ( Dendy, 1905)   (Red Sea and Sri Lanka). Arthuria spirallata   sp. nov. differs from all of these by the presence of three categories of triactines and one of tetractines (tetractines being very rare). The frequent spiral shape of the apical actines is also very characteristic. Four specimens of A. spirallata   sp. nov. were sequenced and included in our molecular tree.

MNRJ

Museu Nacional/Universidade Federal de Rio de Janeiro