Paraleucilla crosslandi ( Row, 1909 )

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 132-134

Paraleucilla crosslandi ( Row, 1909)

Figs 82a–h

Leucilla crosslandi Row, 1909: 207 , fig. 6.

Leucandra innominata Dendy & Row, 1913: 774 .

Paraleucilla crosslandi ; Borojević et al. 2002: 1180.

Material examined. ZMA Por. 13439. Israel, Gulf of Aqaba , Red Sea, depth 7 m, scuba, coll. M. Wunsch, field nr. AQ 7, 30 June 1998.

Description. Fragment of a short, squat, tube ( Fig. 82a ), white in life and in alcohol. Size 9 mm high, 6 mm in diameter, terminal oscule 3 mm. Consistency firm.

Aquiferous system. Leuconoid.

Skeleton. ( Fig 82b ) In cross section of the wall there is a cortical skeleton of triactines and the unpaired and paired actines of cortical tetractines. The subcortical skeleton is inarticulate consisting of the apical actines of the cortical tetractines and the unpaired actines of ‘subatrial’ tetractines, which have a position in the middle of the wall. The mid-skeletal and subatrial region contains a confused mass of smaller tetractines, carried by a layer of smaller triactines lining the atrial cavity.

Spicules. ( Figs 82c–h ) Cortical triactines, giant tetractines, choanosomal triactines, subatrial tetractines, atrial triactines.

Large triactines, cortical ( Fig. 82c ) and mid-skeleton ( Fig. 89e ), which are indistinguishable morphologically; regular or slightly sagittal, actines 198–273–336 x 10 – 17.9 –27 µm.

Giant tetractines ( Fig. 82d ), cortical, and mid-skeleton tetractines (these are not easily distinguishable morphologically), sagittal to irregular, often with arched paired actines and opposing unpaired and apical actines; unpaired actines 204– 481 –720 x 23 – 76.7 –98 µm, paired actines 540– 722 –920 x 21 – 56.3 –88 µm, apical actines 233– 718 –1030 x 39 – 70.1 –78 µm.

Small tetractines of the subatrial skeleton ( Fig. 82f ), sagittal, upaired actines 80– 155 –211 x 8 – 10.2 –11 µm, paired actines 120–191–282 x 8 – 10.4 –11 µm, apical actines 24– 35 – 48 x 7 – 8.2 –9 µm.

Small triactines of the atrial skeleton ( Fig. 82g ), 63– 118 –200 x 8 – 10.3 –14 µm.

Distribution and ecology. Red Sea, shallow depth.

Remarks. The present specimen conforms closely with Row’s description. However, descriptions by Haeckel (1872, p. 156–157), of Leucaltis bathybia var. perimina (from a depth of 615 m) and L. b. var. arabica (shallow depth) from the Red Sea remind of the present species. Various authors assigned these names to different genera: Leucaltis , Leuconia , Leucilla and Sycettusa . There are insufficient details in Haeckel’s decriptions to decide whether Leucaltis bathybia is a senior synonym of Paraleucilla crosslandi . Burton (1952) reported L. bathybia (as Leuconia ) from the Gulf of Aqaba giving measurements of the giant tetractines only, ranginging from 400–960 x 32 –90 µm. Given these large sizes it is possible that Burton’s specimens conform to P. crosslandi , but in the absence of further spicule measurements this cannot be ascertained. Remarkably, Burton did not discuss Row’s species. Unfortunately, also Lévi (1965) when reporting this species (as Leuconia bathybia ) failed to give a description.

Dendy & Row’s (1913) new name Leucandra innominata , erected to remove the junior secondary homonymy of Row’s Leucilla crosslandi with Thacker’s (1908) Leucandra crosslandi , is no longer necessary because the homonymy of the two species names involved has been removed as they are reassigned to different genera. Because the replacement name Leucandra innominata was only used once in Burton’s (1963: 546) listing under the alleged senior synonym Amphoriscus saccharata (along with Leucilla crosslandi ), which does not count as ‘use’ in the sense of ICZN art. 59.3, the name Paraleucilla crosslandi ( Row, 1909) is reinstated.

Unfortunately, we were unable to obtain a partial 28S sequence for this species.

Figures

FIGURE 82. Paraleucilla crosslandi (Row, 1909), ZMA Por. 13439, from Gulf of Aqaba, a, habitus (scale bar = 1 cm), b, light microscopic images of cross section of skeleton, c–g, SEM images of the spicules, c, cortical triactine, d, (sub)cortical tetractines, e, large choanosomal triactines, f, large subatrial tetractines, g, atrial triactines.

FIGURE 89. Kebira tetractinifera sp.nov., holotype ZMA Por. 15245, SEM images of the spicules, a, giant and smaller diactines, b, nail-shaped triactines, b, details of nail-shaped triactines, c, triactines with long unpaired actines, d, triactine with short unpaired actine, e, tetractines with short unpaired actines.