Clathrina, GRAY, 1867

Rapp, Hans Tore, 2006, Calcareous sponges of the genera Clathrina and Guancha (Calcinea, Calcarea, Porifera) of Norway (north-east Atlantic) with the description of five new species, Zoological Journal of the Linnean Society 147 (3), pp. 331-365 : 334-339

GENUS CLATHRINA GRAY, 1867

Type species: Clathrina clathrus (Schmidt, 1864) .

Clathrinidae in which the choanoderm is flat or rarely raised up into conuli by the apical actines of the tetractines, but never forms true folds, at least when the sponge is in the extended state. The full-grown cormus is composed of anastomosed tubes. The skeleton is composed of regular, equiangular and equiradiate triactines and/or tetractines, to which diactines or tripods may be added.

Remarks on Clathrina

The genus Clathrina is represented by more than 40 described species in all seas ( Klautau & Valentine, 2003). The classification is difficult due to the existence of only few, easily recognizable morphological criteria that can be used as descriptors, especially in species whose skeleton is composed only of triactines ( Borojevic & Boury-Esnault, 1987). The paucity of morphological characters, combined with lack of information concerning growth, ecological distribution and reproductive cycle, has frequently mislead to give the impression of a cosmopolitan distribution of species. ‘Cosmopolitanism’ of some sponge species seems to be mainly a result from the systematic difficulty and not from adaptability. Moreover, sympatric populations, which are morphologically almost identical, supported by genetic evidence sometimes seemed to represent sibling species, and shows the importance of use of slight morphological differences (e.g. spicule size or spicule arrangement) to distinguish species of Clathrina ( Klautau, Solé-Cava & Borojevic, 1994) . The use of statistical analyses of shape, size and distribution of spicules has thrown new light on the classification of the group, and previous numbers of species in any given geographical area are expected to be underestimated ( Wörheide & Hooper, 1999; Borojevic & Klautau, 2000; Klautau & Borojevic, 2001; Rapp et al., 2001; Klautau & Valentine, 2003; Rapp, 2004b).

CLATHRINA CORALLICOLA SP. NOV.

( FIGS 1A–D , 2 , TABLE 1)

Type locality: Trondheimsfjord, stn. T-96061704 (63°28.3′N, 10°00.2′E), 200–275 m, 17.06.1996.

Holotype: VM-001 . Museum of Natural History and Archaeology, NTNU.

Paratype: ZMUB-68273 , Røberg , Trondheimsfjord, Norway (63°28.6′N, 09°59′E), 250–300 m, 21.02.1996, one specimen .

Etymology: From Latin, ‘on coral’ referring to the sole occurrence on dead parts of the scleractinian corals Lophelia pertusa (L. 1758) ( Norway and Shetland) and Solenosmilia variabilis Duncan, 1873 ( Iceland) .

Previous records: None.

Additional material examined: 23 specimens.

IB. Korsfjord , 60°09.1′N, 05°08.5′E, 500 m, 17.01.2002 , 2 specimens. Røberg , Trondheimsfjord, Norway, stn. T-96052002 (63°55.6′N, 09°53.5′E), 200–530 m, 3 specimens . Røberg , Trondheimsfjord, Norway, stn. T- 96061704 (63°28.3′N, 10°00.2′E), 200–275 m, 2 specimens . TMU. TM-141, Vågsfjord by Trondenes, 68°00′N, 16°39.8′E, 90–150 m, 28.08.1954 , 2 specimens. TM-142, Gildeskål , 67°1.48′N, 14°1.3′E, 100–200 m, 21.08.1954 , 1 specimen. VM. VM-16831 , Medfjordgrunnen by Garten, 63°38′N, 09°31′E, 140–200 m, 06.07.1923 , 1 specimen. VM-16832 , Fedje , 60°46′N, 04°26′E, 315 m, 09.03.1998 , 1 specimen. VM-16833 , Røberg , Trondheimsfjord, stn. HM 001, 250–350 m, 21.02.1996 , 4 specimens. VM-16834 , Steinavaer , 69°10′N, 16°38′E, 300–320 m, 26.07.1934 , 7 specimens (fragmentary).

Description

Cormus composed of large tubes, irregular and very loosely anastomosed. Some of the tubes end in a culde-sac whereas others have the function of oscular tubes. In the apical region there is no anastomosis. The size is up to 4 cm. No water-collecting tubes are present. Surface is smooth and the walls are 30–40 µm thick and highly translucent. Colour is greyish white when alive and in ethanol. The walls are perforated by evenly distributed ostia. The skeleton comprises regular to subregular triactines of two size groups and regular to subregular tetractines of two size groups. Scattered sagittal tetractines are found in the apical region of the oscular tubes. All spicules with conical and sharp-pointed actines. Large tetractines with a short, cone-shaped and irregular apical actine. The small tetractines have a short, slender and irregularly curved apical actine. The spicules have no special orientation except that the small triactines and tetractines are found on the outer surface, and most of the large tetractines are lining the atrium. The apical actine of the tetractines is orientated towards the interior of the tubes. Triactines of the smallest size group and the large tetractines are the most numerous spicules, whereas large triactines and small tetractines are quite rare.

Distribution

The species is found along the entire Norwegian coast except in the southernmost part, 90– 500 m. The species is also known from 1300 m depth at the Reykjanes Ridge, Iceland (on Solenosmilia variabilis ), and west of the Shetland Islands on dead Lophelia pertusa at 140–530 m depth (my pers. observ.).

Remarks

The species is closely associated with the dead parts of Lophelia pertusa . The irregularly anastomosing tubes are attached to the coral at any part of the cormus that is close to the coral branches. Although the shape of the different types of spicules is very constant, the length of the actines within the different groups of spicules is variable. However, there are no difficulties in delimiting the different groups of spicules. The species resembles most Clathrina ascandroides Borojevic, 1971 . However, the growthform of C. ascandroides is almost always small solitary tubes or tubes anastomosing near the base (1–1.5 mm wide). All the specimens of C. corallicola sp. nov. have irregular cormi composed of 2- to 5- mm-wide tubes that are slightly anastomosed at the base and free in the apical region. Both species have two types of regular to subregular tetractines. However, C. corallicola also has two types of regular to subregular triactines, whereas C. ascandroides has only one. The larger tetractines have the same length of actines in both species, but they are about twice as thick in C. ascandroides than in C. corallicola ( Borojevic, 1971; Klautau & Borojevic, 2001; Klautau & Valentine, 2003). In addition, C. corallicola has sagittal tetractines.

CLATHRINA CORIACEA ( MONTAGU, 1818)

( FIGS 3A–C , 4 , TABLE 2)

Original description: Spongia coriacea Montagu, 1818: 116 .

Synonyms and citations

Ascetta coriacea ( Arnesen, 1901a: 10–11, 1901b: 67–68). Clathrina coriacea ( Rapp, 1999: 45–50; van Soest, 2001: 101; Klautau & Valentine, 2003: 22–23).

Leucosolenia coriacea (Alander in Jägerskiöld, 1971: 60).

Type locality: Budleigh Salterton, South Devon, England.

Neotype: BMNH 1882.3 .6.7 (Dry). Budleigh Salterton, South Devon, England. H.J. Carter Collection ( Klautau & Valentine, 2003). Type specimen not examined.

Previous records: The only true records are from the Bergen area by Arnesen (1901a, b) and from the Trondheimsfjord ( Rapp, 1999).

Material examined: 47 specimens.

IB. Aursøy, Mausundvaer, 63°53′N, 08°38′E, 1 m, 17.04.2000, 4 specimens . Folafoten, Trondheimsfjorden, 63°27.3′N, 10°44.0′E, 14–35 m, 08.01.1996, 1 specimen. Saltvikhamna, Trondheimsfjorden, 63°46.5′N, 11°00.2′E, 25–150 m, 10.11.1995, 1 specimen. AErholmen, Stora Kalsøy, 60°08′N, 05°02′E, 15–45 m, 06.08.2001, 6 specimens. Saebuøya, Hitra, 63°29′N, 08°14′E, 10–15 m, 27.04.2001, 2 specimens. Blåskykøya, Hitra, 63°34′N, 08°18′E, 3–7 m, 29.04.2001, 3 specimens. Horgo, Austevoll, 60°08′N, 05°06′E, 10 m, 13.03.2001, 1 specimen. Vatlestraumen, 60°20′N, 05°11′E, 20 m, 15.05.2001, 1 specimen. Vaerøy, 67°40′N, 12°40′E, littoral, 04.06.1928, 1 specimen. TMU. TM-143, Tromsø, 69°40′N, 19°00′E, 40–60 m, 1 specimen . TM-144, Vannøy, 70°14′N, 19°29.2′E, 100 m, 10.06.1924, 2 specimens. VM. VM- 16835 , Finnsnes, 69°14′N, 17°58′E, 25–40 m, 18.06.1914, 1 specimen . VM-16836 , Rystrømmen, 69°33′N, 18°44′E, 35 m, 15.05.1925, 1 specimen . VM- 16837 , Kristiansund, 63°10′N, 07°40′E, littoral, 22.04.1937, 1 specimen . VM-16838 , Bjarkøy, 68°58′N, 16°42′E, 30–60 m, 06.09.1912, 1 specimen (fragmentary) . VM-16839 , Helløy, Støtt, 66°54′N, 14°24′E, littoral, 29.07.1934, 1 specimen (fragmentary) . VM-16840 , Storhallaren, Frøya, 63°41′N, 08°37′E, littoral, 17.07.1935, 1 specimen . VM-16841 , Meltefjord, Sørøya, 70°30′N, 22°23′E, 1 specimen . VM-16842 / 16843, Knarlagsundet, 63°40′N, 09°05′E, littoral, 13.08.1938, 3 specimens . VM-16844 /16845, Breivik, Herdlevaer, 60°34′N, 04°52′E, littoral, 16.09.1936, 4 specimens . VM-16846 , Titran, 63°40′N, 08°18′E, littoral, 17.04.1931, 2 specimens . VM-16847 , Blåskykøya, Hitra, 63°34′N, 08°18′E, 3–7 m, 28.04.2001, 2 specimens . VM-16848 , Vallersund, 63°52′N, 09°44′E, littoral, 10.08.1926, 1 specimen . VM-16849 , Bjørøya, 64°34′N, 10°50′E, littoral, 09.08.1927, 1 specimen . VM-16850 , Titran, 63°40′N, 08°18′E, 19– 23.04.1928, littoral, 1 specimen . VM- 16851 , Ålesundsaksla, 62°28′N, 06°08′E, littoral, 09.08.1930, 1 specimen . VM-16852 , Storfjellet, Røst, 67°27′N, 11°57′E, littoral, 15.07.1930, 1 specimen . ZMUB. ZMUB-114 , Bergen, 1 specimen (fragmentary) . ZMUB-10882 , Bergen, 55–65 m, 1 specimen (fragmentary).

Description

Cormus somewhat flattened or cushion-shaped, made of small, thin and loosely anastomosing tubes. Watercollecting tubes are present, and osculi are scattered over most parts of the cormus. Surface is smooth, and the texture is soft and somewhat elastic. Colour usually bright white, greyish white, light beige or yellow when alive, and greyish white to brown in alcohol. The cormus is normally up to 30 cm in diameter. The wall of the single tubes is composed of several layers of spicules and is about 40 µm thick. The skeleton has no special organization, and is composed of equiangular and equiradiate triactines. Actines are conical or slightly conical, undulated at the distal part, and have a constriction near the end, which is rounded or blunt.

Distribution

The species is known from the entire Norwegian coast except from the southernmost part, littoral to 150 m. The species is most frequent in the littoral and shallow sublittoral. The species is common in shallow water in the north-east Atlantic.

Remarks

The species is often found at exposed and moderately exposed localities on the outer coasts, but is also common in slightly more sheltered areas in the outer parts of the fjords. At some localities it may cover areas up to 1 m in diameter or form horizontal bands 20–30 cm wide and several metres long immediately beneath the kelp zone ( Laminaria hyperborea (Gunnerus) Foslie, 1884 ). The very irregular outline of ‘specimens’ of this size may indicate that they represent several fused specimens of different size and age as previously reported in a Clathrina from California ( Johnson, 1979).

Recently, several new species of yellow Clathrina have been described from Australia, Brazil and New Caledonia, species that are only slightly different from other related species in respect of spicule characteristics ( Wörheide & Hooper, 1999; Borojevic & Klautau, 2000; Klautau & Borojevic, 2001). However, several yellow specimens of Clathrina coriacea from the Norwegian coast have been investigated. No significant differences in the spicules or morphology of the cormus when compared with the white specimens were observed. It is concluded that at least in C. coriacea the colour of the live sponge is variable, and there is no reason to regard the yellow variety as a distinct species.

Re-examination of museum material revealed that the published records from the Norwegian coast by Haeckel (1872) and Burton (1930b) were Clathrina cribrata and C. nanseni , respectively, and that most of the records by Arnesen (1901a, b) were actually specimens belonging to Guancha arnesenae sp. nov., G. blanca and Clathrina nanseni . The report on Leucosolenia coriacea by Breitfuss (1897, 1898c) only refers to Haeckel’s misidentified specimen of C. cribrata . Size of spicules and organization of the cormus in the examined specimens agree very well with the type material. Spicule measurements of the neotype are from Klautau & Valentine (2003).

CLATHRINA CRIBRATA RAPP ET AL., 2001

( FIGS 5A–D , 6 , TABLE 3)

Original description: Clathrina cribrata Rapp et al., 2001: 70–71 , figure 1A–C.

Synonyms and citations

Clathrina cribrata ( Klautau & Valentine, 2003: 23–24) . Clathrina coriacea ( Haeckel, 1872 pars.).

Clathrina primordialis ( Burton, 1930b: 488, 1963).

Type locality: Kristiansund , western Norway. No coordinates indicated on the original label. Approximate location, 63°10′N, 07°40′E .

Figures

Figure 1. A, holotype of Clathrina corallicola sp. nov. Scale bar = 1 cm. B, spicules of C. corallicola. lte = large tetractines, ste = small tetractines and str = small triactines. Scale bar = 200 µm. C, SEM photo of spicules of C. corallicola. ap = apical actine of sagittal tetractine. Scale bar = 200 µm. D, distribution of spicules seen from the atrial side of the tube wall. Note that the apical actines of the tetractines are orientated towards the interior of the tube. Scale bar = 200 µm.

Figure 2. Distribution of Clathrina corallicola sp. nov. along the Norwegian coast.

Figure 3. A, Clathrina coriacea at 10 m depth. Scale bar = 5 cm. Note the many chimney-like oscula (arrow). B, habitus of a smaller fixed specimen. os = osculum. Scale bar = 1 cm. C, regular triactines from C. coriacea. Scale bar = 100 µm.

Figure 4. Distribution of Clathrina coriacea along the Norwegian coast.

Figure 5. A, Clathrina cribrata at 5 m depth. Scale bar = 1 cm. B, holotype of Clathrina cribrata. Note the many erect oscular tubes (arrow). Scale bar = 1 cm. C, regular triactines. Scale bar = 100 µm. D, transverse section of the osculum, showing the sieve of cells (cribrum). Scale bar = 100 µm.

Figure 6. Distribution of Clathrina cribrata along the Norwegian coast.