A new species of the genus Biemna Gray, 1867 (Porifera: Biemnidae) from shallow waters of the Northwestern Iberian coasts Author Cristobo, Javier IEO-CSIC. Centro Oceanográfico de Gijón (COG-IEO), Avda Principe de Asturias 72 bis, 33212 Gijón, Spain. & Departamento de Zoología y Antropología Física. Universidad de Alcalá, Madrid, Spain. Author Almón, Bruno IEO-CSIC. Centro Oceanográfico de Vigo, Subida a Radio Faro, 50 - 52, 36390 Vigo. Spain. & Grupo de Estudo do Medio Mariño (GEMM), Puerto Deportivo s / n 15960 Riveira, Spain. Author Pérez, Jacinto Grupo de Estudo do Medio Mariño (GEMM), Puerto Deportivo s / n 15960 Riveira, Spain. Author Ríos, Pilar IEO-CSIC. Centro Oceanográfico de Gijón (COG-IEO), Avda Principe de Asturias 72 bis, 33212 Gijón, Spain. & Departamento de Zoología y Antropología Física. Universidad de Alcalá, Madrid, Spain. text Zootaxa 2024 2024-04-29 5446 1 121 132 http://dx.doi.org/10.11646/zootaxa.5446.1.7 journal article 295049 10.11646/zootaxa.5446.1.7 2e850e71-82e5-4ba3-b3ac-82aa45f3ee9a 1175-5326 11084687 36E26547-E5BA-4167-B9BE-93D0199921DF Biemna begonae sp. nov. urn:lsid:zoobank.org:act: 3083D499-E15E-4A30-A49A-B34DD7972194 Figs 2–4 Type material. Holotype . SPAIN • 1 specimen ; Galicia , Ría de Arousa , “O Oasis”; 42º30.5860’ N , 8º 56.5880’ W ; 14 Aug. 2019 ; 30 m depth ; J. Pérez leg.; MNCN 1.01 /1021. Paratype 1. SPAIN • 1 specimen ; Galicia , Ría de Arousa , “A Tritonia”; 42º 30.4050’ N / 8º 56.4490’ W ; 28 Feb. 2021 ; 26 m depth ; J. Pérez leg.; MNCN 1.01 /1022. Paratype 2. SPAIN • 2 specimens ; same locality as for Paratype 1; 14 July 2022 ; 28 m depth ; J. Pérez leg.; MHN USC 10135 . Diagnosis: The only Biemna known to date with a combination of four size categories of sigmata, raphides in trichodragmata, styles and rahbdostyles. Habitus: cushion shaped or thickly encrusting, burgundy red to pale or whitish cream colour, with numerous papillae. Description. Habitus. Cushion shaped or thickly encrusting, with numerous (30-50) papillae emerging from the surface. These papillae are flat, pinnate or feather shaped 0.5 cm width and 2.5 cm high. Holotype ( Fig. 2A ) is approximately 7.5 x 6.4 x 5 cm ; main body up to 6.2 cm in diameter and 3.0 cm high; the upper surface is slightly hispid. Colouration: a chromatic variety has been found from burgundy red to pale or whitish cream colour ( Fig. 2C–E ). Skeleton Fig. 3 . The choanosomal skeleton ( Fig. 3 A, E ) is composed by paucispicular bundles (3–8 spicules) of styles that splits dichotomously loosely crossed.At the junctions spongin is more abundant providing reinforcement. Sigmata and raphides are very abundant throughout the skeleton, surrounding the bundles and embedded in the spongin. The raphides are loose and form trichodragmas. In the ectosome, the bundles of styles protrude providing the sponge with a slight hispidation. Microscleres are very abundant. The skeleton of the papillae ( Fig. 3 A-D) consists of ascending paucispicular tracts of styles that run flexuously the length of the papillae. These tracts end at the apex and side of the papilla in two or three spicules protruding to the outside. Sigmata of all sizes are very abundant and reinforce spongin. Rhabdostyles are not very abundant and without a significant position within the skeleton. Spicules ( Fig. 4 ). Megascleres. Styles ( Fig. 4 A, A . 1 ): smooth and slightly curved, with regular rounded heads and acerate points. Dimensions: 464–(653)–747 µm x 6.4–(12.7)–16.7 µm. Rhabdostyles ( Fig. 4 B, B . 1 ). Straight or very slightly curved, with strong curvature very close to the basal end. Rare. Dimensions: 89–(211)–371 x 2.5–(7.3)–12.4 µm. Microscleres ( Fig. 4 C–H ). Sigmata: four size clases ( Fig. 4 D-H). C–shaped, smooth in the shaft but with short spines in both ends. Dimensions: Sigmata I: 79–(112)–141 µm x 1.4–(3.8)–5.8 µm. Sigmata II: 30–(44)–71 µm x 2.0–(3.0)–4.4 µm Sigmata III: 19–(23)–32 µm x 0.8–(1.6)–2.8 µm Sigmata IV: 11.3–(14.5)–18.8 x 0.4–(1.0) –1.8 µm Raphides ( Fig. 4 C, C . 1 ). Very small, only slightly curved. Aligned or randomly distributed spines can be present. They may lay single in the skeleton of the sponge or forming trichodragmata. Dimensions: 92–(115)–174 µm x 0.5–(1.3)–2.4 µm In order to evaluate the intraspecific variability, Table I shows the measurements of the different spicule classes for each of the specimens of the new species. The size distributions are illustrated in Figure 5 , revealing that styles, rhabdostyles and raphides follow a standard normal distribution. The size distribution of the sigmata when considering the variety of sizes in the different specimens, reflects four distinct peaks. The widest and most flattened corresponds to the larger Sigmata I, while the most marked, although with a certain degree of overlap, define Sigmata II, III and IV. FIGURE 2. Biemna begonae sp. nov. , four different specimens showing in vivo appearance, growth stages and colour. A. Holotype. B. Paratype1. C–E. Paratypes 2. FIGURE 3. Biemna begonae sp. nov. A. Schema of the skeletal arrangement in one of the papillae. B. Close up with a light microscope of the end of the ectosomal papilla. C. Close up with SEM of the end of the ectosomal papilla. D. Close up of ectosomal spicules. E. Choanosomal skeleton by SEM. FIGURE 4. Biemna begonae sp. nov. SEM images of spicules A. Style. A.1. details of A. B. Rhabdostyle. B.1. Details of B. C. Raphide, C.1. Details of C. D. The four size classes of sigmata. E. Sigma I. E.1 Details of E. F. Sigma II. F.1. Details of F. G. Sigma III. G.I. Details of G. H. Sigma IV. H.1 Details of H. TABLE I. Spicular dimensions of all Biemna begonae n. sp. specimens. Dimensions in microns based on 25 measurements of each element.

µm	HOLOTYPE	PARATYPE I	PARATYPE 2A	PARATYPE 2B	ALL
Styles	541.21-(662.74)-	464.37-(660.05)-	568.00-(652.37)-	527.50-(640.57)-	464.37-(653.93)-
747.25 X 6.59-	745.93 X 10.11-	741.95 X 8.79-	719-69 X 6.40-	747.25 X 6.40-
(13.53)-16.16	(13.96)-15.77	(12.49)16.79	(11.09)-15.21	(12.77)-16.79
Rhabdostyles	89.12-(216.48)-	118.88-(189.81)-	169.94-(219.79)-	148.22-(222.89)-	89.12-(211.21)-
343.47 X 2.54-	336.75 X 3.63-	302.70 X 5.62-	371.54 X 4.82-	371.54 X 2.54-
(7.51)-10.23	(7.08)-12.44	(7.78)-10.43	(7.37)-10.43	(7.39)-12.44
Raphides	104.64-(119.20)-	100.87-(118.05)-	92.81-(111.27)-	92.71-(110.73)-	92.71-(114.85)-
173.69 X 0.56-	153.28 X 0.90-	119.86 X 0.79-	128.14 X 0.80-	173.69 X 0.56-
(1.18)-1.79	(1.28)-2.01	(1.49)-2.41	(1.27)-2.01	(1,31)-2.41
Sigma I	87.43-(117.14)-	86.73-(115.71)-	79.31-(103.21)-	83.47-(113.27)-	79.31-(112.34)-
136.78 X 2.89-	141.91 X 2.57-	134.12 X 1.45-	130.06 X 2.34-	141.91 X 1.45-
(4.19)-5.08	(4.03)-5.31	(3.22)-4.82	(3.76)-5.85	(3.80)-5.85
Sigma II	31.11-(46.76)-71.63	30.51-(42.36)-52.84	37.15-(45.26)-59.19	35.83-(44.11)-66.27	30.51-(44.62)-71.63
X 2.34-(3.10)-3.70	X 2.01-(3.04)-4.19	X 2.01-(2.96)-4.01	X 2.01-(3.06)-4.41	X 2.01-(3.04)-4.41
Sigma III	19.21-(22.18)-27.08	19.31-(24.66)-31.25	19.33-(22.77)-28.91	19.20-(23.62)-32.78	19.20-(23.31)-32.78
X 1.21-(1.64)-2.42	X 1.21-(1.71)-2.41	X 1.00-(1.89-2.81	X 0.80-(1.40)-2.81	X 0.80-(1.66)-2.81
Sigma IV	11.51-(14.44)-18.17	11.92-(15.12)-18.04	12.60-(14.44)-18.84	11.30-(14.30)-18.25	11.30-(14.58)-18.84
X 0.57-(0.89)-1.42	X 0.40-(0.89)-1.27	X 0.79-(1.33)-1.65	X 0.85-(1.22)-1.79	X 0.40-(1.08)-1.79

FIGURE 5. Biemna begonae sp. nov. Size distribution of spicules of the holotype and paratypes. A. Styles lengths (n=100); B. Rhadostyles lengths (n=90); C. Raphides lengths (n=100); D. Sigmata lengths (n=400). Distribution and ecology. Galician coast (NW of Spain). This species was found from 20 to 30 metres depth, on detrital hard bottoms, mainly on horizontal rocky surfaces covered by thin layers of sediment. Its base may be covered with sediment, with only the projections visible. Specimens collected in July (MHN USC 10135) showed reproductive buds along the papillae, located on the distal ends of the spicules emerging from the surface ( Figure 2E ). Etymology. The species is dedicated to the memory of Begoña Pérez Dieste (1965–2021), sister of Jacinto Pérez, co-author of this work and a great enthusiast and defender of the marine environment, who passed away prematurely.