Racekiela cresciscrystae, Cruz-Barraza & Camacho-Cancino, 2019

Patricia Gómez, José Luis Carballo, Cruz-Barraza, José Antonio & Camacho-Cancino, Mildred, 2019, On the genus Racekiela in Mexico: molecular and morphological description of Racekiela cresciscrystae n. sp., Journal of Natural History 53 (21), pp. 1351-1368 : 1356-1362

publication ID	https://doi.org/10.1080/00222933.2019.1637475
DOI	https://doi.org/10.5281/zenodo.3679851
persistent identifier	https://treatment.plazi.org/id/03FA3B30-FF82-D34A-FE5A-A33EFC80FB14
treatment provided by	Valdenar
scientific name	Racekiela cresciscrystae
status	sp. nov.

Treatment

Racekiela cresciscrystae sp. nov.

Material examined

Holotype. CNPGG ‒ 2331 La Capilla River ( Villa del Carbónı México Stateı México)ı 19° 43 ʹ 53.4´´ Nı 99°30´49.32´´ Wı 25.III.2017.

Paratypes. CNPGG‒2026 La Capilla River (Villa del Carbónı México Stateı México)ı 19° 43 ʹ 55.1994 ʹ ’ Nı 99°30 ʹ 49.32 ʹ ’ W; 26 .III.2017. CNPGG‒2030 La Capilla River ( México Stateı México)ı 19°43 ʹ 57.72 ʹ ’ Nı 99°30 ʹ 50.3994 ʹ ’ W; 25.III.2017. CNPGG‒2332 La Capilla River ( México State)ı 19°43 ʹ 53.4 ʹ ’ Nı 99°30´50.3994 ʹ ’ W; 25.III.2017 . CNPGG‒2334 La Capilla River ( México State)ı 19°43´57.72´´ Nı 99°30 ʹ 51.12 ʹ ’ W; 26.VI.2017 . CNPGG‒2335 La Capilla River ( México State)ı 19°44 ʹ 1.694 ʹ ’ Nı 99°30 ʹ 32.24 ʹ ’ W; 26.VI.2017 . CNPGG‒2336 La Cañada (Villa del Carbónı Estado de México)ı 19°46 ʹ 42.6 ʹ ’ Nı 99°28 ʹ 42.594 ʹ ’ W; 27 . VI.2017 . CNPGG‒2337 La Capilla River ( México State)ı 19°43 ʹ 58.08 ʹ ’ Nı 99°30 ʹ 48.944 ʹ ’ W; 26.VI.2017 .

Etymology

Cresciscrystae is a compound name from the words crescis in Latin meaning rising and crista that means ridge; the main sponge surface trait.

Ecology

Racekiela cresciscrystae sp. nov. occurs in calmı and running watersı but always in shallow waters (less than 1 m depth) and encrusted on a solid substrate ( Figures 2 View Figure 2 and 3 View Figure 3 ). In calm waterı the species always grows as a thick encrusting sponge with bulbous outgrowths. Insteadı in running waterı the species has always been found as a thinner encrusting sponge. It is dark green colour in shadeı and lime-green exposed to light. Water quality conditions recorded for the different river sites are: Temperature 13.3 ‒ 14.7°Cı pH 6.7 ‒ 7.6ı dissolved oxygen 5.70 ‒ 8.3 mg /lı conductivity 0.054 ‒ 0.371 ms/cmı salinity 004 – 006 ppm.

General morphology

The new species depicts two morphotypes; the more common is a thick encrusting form with raised ridges or bulbous outgrowths at the surface and dark green in colour when alive. It measures 36 cm long by 19.5 cm wideı 10 mm to up to 3.0 cm thick; the thickest parts owe to the bulbous outgrowthsı like conesı that measure 2.0 cm highı and 2.0 cm at the base ( Figure 2 View Figure 2 ). The second morph is a flattened thinner encrustation measuring up to 3.0 mm thick with a lime-green colour ( Figure 3 View Figure 3 ). The twoı are ochre yellow in dried stateı and light beige in alcohol. Compressible in consistency but fragileı smooth surface but microhispidı pierced by megascleres due to the skeletal arrangement. Several round oscula visible to the eyeı up to 7 mm in diameter. Ectosomal skeleton with tangential megascleres irregularly scatteredı besides upright oxeas with tips protruding the surface ( Figure 4 View Figure 4 ). Choanosomal skeleton conforms an ill-defined isotropic network connected by ill-defined paucispicular tracts of oxeası and scattered megascleres in-between ( Figure 4 View Figure 4 ). Also found in choanosome are some scattered birotules and pseudobirotules.

Gemmules

Exclusively spherical 500 ‒ 690 µm in diameter ( Figure 5 View Figure 5 )ı pale yellow in colourı abundant at the basal portion and rare in the sponge body. It is an armed gemmule arranged by a gemmular tri-layered thecaı characterised by the outer gemmular layerı the pneumaticı and the inner layers. The thicker layer is the pneumatic oneı which has birotules radially embeddedı and pseudobirotulesı which generally protruding from the outer layer. Gemmules include an irregular number of chambers that concur with the inner layer. Inside a dense mass of thesocytes is observed. A single and simple foramen is present.

Spicules

Acanthoxeas always slightly spined all over and hastate ends 200 ‒ 252 ‒ 300 × 7.8 ‒ 10.9 ‒ 13 µmı few of them show centrotyloteı or very seldom malformations intersected fused like ( Figure 6 View Figure 6 ). Many markedly thinly smooth and fusiform oxeas are also present;143 ‒ 206 ‒ 260 × 5.2 ‒ 6.2 ‒ 7.8 µm ( Figure 6 View Figure 6 ); microscleres absent ( Table 1 View Table 1 ).

Gemmuloscleres: birotules with length always greater than rotule diameterı 39 ‒ 51.2 ‒ 59 µm longı straight shaft usually smoothı 5.2 ‒ 5.5 ‒ 7.8 µm in diameterı very seldom bearing one or three acute spines; rotules are flatı some slightly umbonateı 20 ‒ 26 µm in diameter; they have deeply jagged edges with irregular acute raysı ornamented also with finely crenulate spines ( Figures 7 View Figure 7 and 8 View Figure 8 ). Proportion of the diameter of the rotule vs. length of the shaft is from 1.7 to 2.5.

Pseudobirotules with strongly or somewhat spined shaft. Spines can be straight or hookedı 57 ‒ 66.2 ‒ 75 × 5.2 ‒ 6.2 ‒ 10.4 µm. They are characterised by strongly hooked spines slightly umbonateı and sometimes with a prominent spike. Numerousı slightly smaller and thinner pseudobirotules with umbonate endingsı and with only small wartsı instead of spines ( Figures 7 View Figure 7 and 8 View Figure 8 ) ( Table 1 View Table 1 ).