Isabella mirabilis Schlacher-Hoenlinger, Pisera & Hooper, 2005

Ekins, Merrick, Erpenbeck, Dirk, Wörheide, Gert & Hooper, John N. A., 2016, A new species of lithistid sponge hiding within the Isabella mirabilis species complex (Porifera: Demospongiae: Tetractinellida) from seamounts of the Norfolk Ridge, Zootaxa 4136 (3), pp. 433-460 : 435-441

Isabella mirabilis Schlacher-Hoenlinger, Pisera & Hooper, 2005

( Figs 1–5 , Table 1 )

Isabella mirabilis Schlacher-Hoenlinger et al., 2005: 670 -673, Figs 3 A, 12, 26 (in part). Ekins et al. 2015: 437 -451 (in part).

Material examined. Holotype - MNHN DCL 3903 (fragment of holotype QM G318560) Jumeau West seamount, Norfolk Ridge, 23.685 S, 168.017 E, 237–250 m, RV Alis, 21/06/2001, Waren dredge, coll. Bertrand Richer de Forges, Tin-Yam Chan, Bernard Cohen, Enrique MacPherson, Marie-Catherine Boisselier, Pierre Lozouet. Other material - QM G318751 as per the holotype. G329906, G329908, G329909, G329910, G329911, G329912, G329913, G329914, G329915, Jumeau West seamount, Norfolk Ridge 23.685 S, 168.017 E, 285 m, RV Alis, 23/ 10/2003, Waren dredge, coll. B. Richer de Forges, A. Pisera, T. Schlacher. G329916, G329917, G329918, G329919, G329920, G329921, G329922, G329923, G329924, G329925 Kaimon Maru seamount, Norfolk Ridge, 24.753 S, 168.121 E, 320–345 m, RV Alis, 29/10/2003, Waren dredge, coll. B. Richer de Forges, A. Pisera, T. Schlacher. G329926, G329927, G329929, G329930, G329931, G329932, G329933, G329934, G329935 Blanc Nouveau 2, 23.277 S, 168.233 E, 275–348 m, RV Alis, 2/11/2003, Waren dredge, coll. B. Richer de Forges, A. Pisera, T. Schlacher. G329936, G329937, G329938, G329939, G329940, G329941, G329942, G329943, G329944, G329945 Munida seamount, Norfolk Ridge, 22.998 S, 168.363 E, 270–350 m, RV Alis, 3/11/2003, Beam trawl, coll. B. Richer de Forges, A. Pisera, T. Schlacher.

Description. Growth Form. Massive ficiform or egg cup shaped sponge with a shallow apical dish, a short broad based stem and an uneven margin ( Figs 1 , 2 ); outer surface bearing numerous, short (up to 1 cm), unevenly distributed wart like buds ( Fig. 3 ). Dimensions are 3–7.5 cm long, 2.5–7 cm wide and 3–5 cm high. Several specimens have a roughly circular base which is approximately 1 cm less in diameter than the body.

Colour. Wine Dark purple/brown in ethanol.

Oscules. Numerous microscopic exhalant oscules 0.05–0.2 mm in diameter.

Texture. Hard, slightly compressible but brittle.

Surface ornamentation. Uneven and slightly hispid caused by oxeas protruding several millimetres above the surface.

Ectosomal skeleton. The ectosomal skeleton consists of an exterior skin like crust of microscleres with smooth dichotriaenes and occasionally triaenes perpendicular to the surface. The microscleres consist of abundant asymmetrical euasters like streptasters resembling jacks, and microxeas. The microxeas consist of smooth and microspinose curved oxeas that are predominantly centrotylote.

Choanosomal skeleton. The choanosomal skeleton consists of a 3D matrix of regular and slightly curved dicranoclone desmas. These desmas form a distinct root/vine like mesh (as described in Schlacher-Hoenlinger et al. 2005). Choanosomal microscleres consist of microspinose spiraster streptasters with slender arms. There are bundles of smooth very long oxeas in long thick brushes piercing the surface.

Megascleres. Desmas are slender tripodal dicranoclone as described previously ( Schlacher-Hoenlinger et al. 2005). The desmas range in size from 339–766–1370 x 20–60 –347 µm. Dichotriaenes with rounded and sharp rhabdome tips are extremely variable in shape resembling every shape from a promonaene, triaene, dichotriaenes , dichodichotriaene, trichotriaene to pentatriaene (see Fig. 5 ). Variability in dichotriaene shape has been noted in other lithistids such as Reidispongia coerulea Pisera & Lévi, 2002 . Triaenes are occasionally found, often resembling an immature dichotriaene. Oxeas are very long, thin and sharp originating in the choanosome and extending in bundles out to the exterior of the sponge. (Refer to Table 1 for megasclere dimensions).

Microscleres. Centrotylote microacanthoxeas are very common, very rarely (<0.5%) with thorns, there are also microacanthoxeas lacking an obvious central swelling. Smooth microxeas also exist which may or may not also have a central swelling. These smooth microxeas have variable tips (See Fig. 4 ). The microscleres also consist of abundant symmetrical microspinose spirasters with long thin arms and symmetrical ‘Jacks’ microspinose streptasters with short thick arms. (Refer to Table 1 for microsclere dimensions).

DNA signature sequence. CO1 sequences are deposited in NCBI Genbank (Accession number KX267959 , KX267960 and KX 270646 –KX 270684) and the Sponge Barcoding Database (Accession number 1642) Specimen Desmas Long shafteđ đichotriaenes Short-shafteđ Long shafteđ triaenes Short-shafteđ Oxeas, long Oxeas long tanoa G335130 450-569-774 x 18.6- Rhabđome 268-380-603 Rhabđome 195-265-363

31.7- 46.9 N= 18 x 9.4-14.5-17.6 x 9.2-13.2-19

Clađome 200-304-382 x 9.2- Clađome 174-323-432 x 13.9- 19.2 N=14 8.7-13.3- 19.2 N =16

tanoa Total 285-584-871 x 10.7- Rhabđome 268-509-923 x Rhabđome 128-234-363

26.5-48.5 8.1-15.2-22.1 x 9.3-13.5-19.0 Clađome 160-365-612 x 9.2- Clađome 124-319-546 x 14.8-20.8 8.7-13.2-19.5

mirabilis (đescription 520-610 x 25-45 Rhabđome 523-784

Schlacher-Hoenlinger Clađome 297-479

al. (2005))

mirabilis (Holotype 628-747-965 x 29.6- Rhabđome 369-565-748 x MNHN DCL 39093 58.2- 60.8 N=18 23.3-32.2-42.7

QM G318560)) Clađome 211-420-584 x

18.7-30.4- 38.7 N =98

……continued on the next page Specimen Desmas Long shafteđ đichotriaenes Short-shafteđ Long shafteđ triaenes Short-shafteđ Oxeas, long Oxeas long đichotriaenes with triaenes thick anđ thin anđ smooth enđs blunt curveđ acerate tips

harboranchi 460-960 x 17.5-37.5 Rhabđome 107-283-578 x 150-349-623 x 107-283- 320-426-570, 33 328-717-1500 100-730-2099 đescription in Carvalho 6.5-9.3-14.8 578 x 3.6-8.7-18.9 x 2.0-2.9-6.3 al. (2014)) Clađome 150-349-623 x 3.6-

9.4-12.9

……continued on the next page Specimen Desmas Long shafteđ đichotriaenes Short-shafteđ Long shafteđ triaenes Short-shafteđ Oxeas, long Oxeas long

đichotriaenes with triaenes thick anđ thin anđ

smooth enđs blunt curveđ acerate

tips 329931 D 597-835-952 x 62.5- Rhabđome 374-577-744 x

78.7-117 N=7 20.1-45.5-64.0

Clađome 149-320-572 x

20.8-40.3- 64.9 N =27

329943 D 694-822-955 x 26.1- Rhabđome 484-629-803 x

39.2- 47.8 N=7 24.6-38.7-58.5

Clađome 307-514-721 x19.0-38.7- 58.5 N=19

318751 E 684-844- 1080 x 20.0- Rhabđome 435-683-880 x

38.4- 59.5 N=11 12.4-24.1-35.1

Clađome 120-254-442 x 12.7-24.7- 42.3 N =21

329908 E 573-927- 1200 x 40.3- Rhabđome 510-667-918 x

46.6- 56.4 N=7 20.0-27.8-42.7

Clađome 195-356-602 x

19.0-32.2- 37.0 N =20

329911 E 694-778-876 x 34.0- Rhabđome 431-535-670 x Rhabđome 109-314-629

59.3- 88.6 N=6 31.1-42.6-49.4 x 16.9-29.0-41.0 Clađome 308-456-618 x Clađome 185-251-316 x 25.6-38.7- 47.0 N =18 16.9-29.8- 42.7 N =2

329939 E 728-851- 1180 x 36.0- Rhabđome 363-443-495 x

49.0 - 63.7 N =8 23.4-37.0-51.7

Clađome 272-516-653 x21.5-33.8- 42.2 N =11

329909 F 500-757- 1370 x 49.1- Rhabđome 443-552-774 x Rhabđome 512-552-770

65.7- 81.4 N=10 21.0-34.3-46.0 x 19.4-32.6-46.6

Clađome 190-354-528 x Clađome 157-316-509 x 16.9-29.0- 44.2 N =21 17.9-29.0- 40.9 N =13

329912 F 604-786- 1050 x 31.3- Rhabđome 340-522-739 x Rhabđome 468-641-799

53.0-71.3 17.8-38.4- 54.2 N = 23 x 11.9-16.7-23.5

N=9 Clađome 144-441-838 x Clađome 90.1-132-354 x 15.8-33.1- 44.3 N =23 11.8-16.3- 23.9 N- 5

……continued on the next page Specimen Desmas Long shafteđ đichotriaenes Short-shafteđ Long shafteđ triaenes Short-shafteđ Oxeas, long Oxeas long

đichotriaenes with triaenes thick anđ thin anđ

smooth enđs blunt curveđ acerate

tips 329913 F 615-714- 1090 x 42.3- Rhabđome 246-538-834 x Rhabđome 366-640-935

66.8- 90.5 N=9 16.6-38.0-57.1 x 18.0-31.8-39.6

Clađome 216-425-618 x Clađome 132-338-636 x

13.7-33.2- 54.7 N =27 13.6-27.1- 39.1 N =5

……continued on the next page Specimen Oxeas very long Centrotylote Smooth Non-centrotylote Centrotylote Spirasters Streptasters Jack Streptasters

anđ curveđ sharp Microacanthoxe Microxeas microacanthoxeas smooth

tips as microxeas

tanoa MNHN 1120-2557 -5640 x 54 - 87-119 x 5. 2-1 5.3- 28.2 x 6.9- 11.5 -21.0

4111 (QM 3.6-8.9- 12.2 N =40 2.9-4.4-6.2 3.5-12.4-20.2 (SD=2.9) x3.8-

318737) N=107 N=155 7.3 - 13.4 N=115

tanoa G318765 908-1530-2300 x 57 -82- 104 x 9. 0-1 5.5-32.3 x 6.4-11.1-19.8 x 2.9-5.2-8.9 3.4-4.7-7.2 6.0-13.2-25.7 4.1-8.2- 16.0 N =22 N=108 N=110 N=105

tanoa G318803 1150-2280-3620 x 42.4-70.3-99.8 6.5-1 3.5-22.3 x 5.6-11.0-28.2 x 3.3-7.7-12.3 x 2.2-3.7-5.2 3.9-10.9-20.8 4.2-7.3- 15.1 N =33 N=121 N=100 N=102

tanoa G335130 1040-1860-4390 x 59 -92-124 x 2.7- 6.7-1 4.7-25.8 x 6.2- 11.9-17.8 x 3.5-5.4-8.4 4.2-5.8 5.8-12.2-20.9 4.7-8.3- 14.6 N =20 N=112 N=100 N=100

tanoa Total 908-2180-5640 x 42.4-87.7-124 x 5. 2-1 4.9-32.3 x 5.6-11.4- 28.2 x 2.9-8.3-12.3 2.0-4.5-7.2 3.5-12.3-25.7 3.8 -7.8-16.0

mirabilis 468 x 7-8 65.9-107 x 3.8- In đescription 17.5-25.9 x 15- 8. 2-1 5.0

đescription in 5.6 photograph but not 20.8

Schlacher- specifically

Hoenlinger et al. measuređ

2005))

mirabilis 1240 -2780-6580 x 61.3-87.6-118 x 69.5-131.7-305 61.8-87.5-114 x 64.7-119-181 x 12.4-18.1-26.8 x 5. 7-9.9-18.9 x 4.5-8.5-

Holotype MNHN 5.1-10.7-17.3 3.2-5.0-7.0 x 2.2-3.7-9.1 3.4-4.8- 6.8 N =44 2.6-4.7-8.2 9.5-15- 21 17.1 N =146 39093 (QM N=26 N=83 N=69 N=46 N=65

318560))

harboranchi 38-70-105 x 2.5- 100 x 2? 62-100-145 x1.9- 7.5-14.4-24.2 2.7-13.4-20.2 đescription in 5.5-9.2 (rare) 5.4-10.9 (abunđant) Carvalho et al.

2014))

329910 C 682-2090-2370 45.0-79.9 -97.5 72.6-133-200 x 60.6-78.6-91.3 x 101-141-204 x 10.0-16.2-22.9 x 6. 7-1 0.2-19.8 x 5.7-8.5-

x6.4-7.0- 7.6 N = 12 x 5.3-6.9-9.75 2.1-3.7-4.8 4.3-6.3- 8.1 N =16 3.5-4.3-5.6 7.2-13.9-19.1 14.1 N =48 N=45 N=37 N=15 N=49

……continued on the next page Remarks. The holotype and other material examined of I. mirabilis differ from the original description (Schlacher- Hoenlinger et al. 2005), by the presence of smooth microxeas, and smooth centrotylote microxeas, the occasional presence of triaenes, and the presence of very long oxeas. In addition measurements of all the mega- and microscleres have found a larger range than initially reported. The variability and concept of this species are discussed in more detail in a comparative context, below.

Figures

FIGURE 1. Specimens of I. mirabilis, on the left, the Holotype MNHN DCL 3903 (QM G 318560), and on the right G 318751.

FIGURE 2. Preserved specimens of I. mirabilis. Back row, from left to right: G 318751, G 329916 and G 329917. Middle row: G 329919, G 329920, G 329921 and G 329924. Front row: G 329925, G 329922 and G 329923.

FIGURE 3. One of the ‘ warts’ from Isabella mirabilis budding off from specimen G 318751, with the large oxeas, dichotriaenes and microscopic oscules clearly visible.

FIGURE 4. Spicules of Isabella mirabilis. A, microacanthoaxeas. B, centrotylote microacanthoxeas. C, centrotylote microacanthoxeas with thorns. D and E, smooth centrotylote microxeas. F, tip of microacanthoxeas. G to I, tip of smooth microxeas. J, range of smooth microxeas. K to M, Spirasters with long thin thorny arms. N to R, streptasters with short thick thorny arms of variable number, length and termination.

FIGURE 5. Dichotriaenes of Isabella mirabilis. A to H, showing the variability of dichotriaenes. I, triaene.

Tables

TABLE 1. The range of spicule measurements (µm) anđ mean (unđerlineđ) for the specimens of I. tanoa sp. nov. anđ I. mirabilis anđ comparison with the publisheđ đescriptions of I. mirabilis Schlacher-Hoenlinger et al., (2005) anđ I. harborbranchi Carvalho et al., (2014).

I.tanoa MNHN DCL 4111 (QM G318737)	285-508-793 x 10.7- 25.0-48.5 N=21	Rhabđome 423-534-923 x 13.0-15.5-19.5 Clađome 230-394-523 x 13.0-15.6-18.5 N=21	đichotriaenes with smooth enđs Rhabđome 128-211-280 x9.3-13.2-17.8 Clađome 270-358-546 x 9.9-13.4-19.5 N=16	triaenes	thick anđ blunt	thin anđ curveđ acerate tips
I. tanoa G318765	506-659-871 x 17.3- 27.2-41.4 N=21	Rhabđome 448-567-707 x10.5-15.5-22.1 Clađome 160-393-612 x 12.7-15.4-20.8 N=21	Rhabđome 164-211-290 x 9.7-13.9-16.8 Clađome 288-356-433 x 10.1-14.0-18.2 N=22
I. tanoa G318803	416-595-815 x 13.3- 24.0-42.0 N=30	Rhabđome 382-508-712 x 8.1-13.9-18.3 Clađome 164-244-314 x 10.2-13.4-15.7 N=7	Rhabđome 175-260-345 x 10.7-13.5-17.0 Clađome 124-229-330 x 9.7-12.1-17.0 N=17