Paraleucilla erpenbecki

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160: 134-138

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Paraleucilla erpenbecki


Paraleucilla erpenbecki  sp.nov.

Figs 83a–d View Figure , 84a–i View Figure

Material examined. Holotype, ZMAAbout ZMA Por. 22409a, Mozambique Channel, between Mozambique and Madagascar, E of Juan de Nova Island, 17.2817°S 43.1567°E, depth 60 m, coll. RV ‘Pelagia’ Around Africa II expedition, leg 6, field nr. 20- ASCAbout ASC 10, 1 April 2001

Paratypes, ZMAAbout ZMA Por. 22409c, five individuals from the same locality as the holotype.

Description. The sample consists of six sycon-like tubular individuals ( Figs 83a,a View Figure 1 View Figure ), one of which was chosen as the holotype ( Fig. 83a View Figure ). Shape oval, narrowing towards the osculum. Height of largest tube (the holotype) is 3 cm, diameter 1.5 cm. Fringe prominent but short, 2–3 mm, slightly flaring. Color in alcohol light beige. Surface slightly hispid, rough-looking. Consistency soft.

Aquiferous system. Leuconoid.

Skeleton. ( Figs 83b–d View Figure ) The wall has a thickness of about 2 mm with protruding trichoxeas and very few diactines causing the hispid surface. In the SEM cross section ( Fig. 83b View Figure ), from the periphery towards the atrium, there is a cortical skeleton ( Fig. 83c View Figure ) of rare triactines carried by the basal actines of a single layer of cortical tetractines. Occasionally, there are scattered diactines protruding from the skeleton to the outside. Next, the choanosomal skeleton is inarticulate ( Fig. 83b View Figure ) formed by the apical actines of the cortical tetractines and unpaired actines of giant triactines lying in the mid-region of the wall. Below these there is a confused mass of smaller tetractines and triactines, and finally the atrial skeleton ( Fig. 83d View Figure ) is formed by tetractines of which the apical actines protrude far into the atrial lumen, and by smaller triactines. The fringe is formed by thin giant diactines grading into thick trichoxeas, and at the base it is supported by triactines and tetractines (not shown).

Spicules. ( Figs 84a–i View Figure ) Giant diactines, trichoxeas, small diactines, large tetractines, large triactines, small tetractines and small triactines.

Giant diactines (Fg. 84a), fusiform, blunt endings, 388– 1066 – 1973 x 19 – 31.8 –42 µm.

Trichoxeas and thin diactines ( Fig. 84b View Figure ), sharp endings but subapically often slightly distended, almost invariably broken, fragements measuring 480– 962 – 1740 x 3 – 4.8 –7 µm.

Small diactines ( Fig. 84c View Figure ), not common, only a few could be measured, 147–210 x 8–9 µm.

Cortical triactines and small triactines of the subatrial region ( Figs 84d View Figure ), these were indistinguishable and not very common, either regular or slightly irregular or sagittal, actines 138– 196 –266 x 8 – 10.9 –16 µm.

Cortical large tetractines ( Fig. 84e View Figure ), not very common, with basal actines often curved and blunt ending, apical actines straight and pointed, thinner than the other actines; unpaired actines 132– 324 –468 x 13 – 30.5 –37 µm, paired actines 216– 304 –429 x 15 – 21.7 –31 µm, apical actines 211– 321 –786 x 18 – 17.1 –23 µm.

Giant triactines ( Figs 84f View Figure ), sagittal with straight unpaired actines and curved paired actines; unpaired actines 151– 320 –603 x 10 – 20.4 –33 µm, paired actines 231– 366 –598 x 12 – 22.2 –36 µm.

Giant tetractines of the subatrial region ( Fig. 84g View Figure ), with straight actines, apical actines short and conical; unpaired actines 231– 394 –696 x 13 – 18.8 –38 µm, paired actines 228– 313 –391 x 12 – 16.7 –26 µm, apical actines 45– 62 – 84 x 7 – 8.3 –10 µm.

Small tetractines of the subatrial region ( Fig. 84h View Figure ), similar in shape to giant tetractines, but smaller, unpaired actines 48– 149 –268 x 7 – 10.4 –13 µm, paired actines 63– 151 –249 x 6 – 9.0 –11 µm, apical actines 31– 47 – 61 x 5 – 7.2 –10 µm.

Atrial tetractines ( Fig. 84i View Figure ), with long straight apical actines and unpaired actines almost similar in length, with curved paired actrines; unpaired actines 152– 232 –418 x 9 – 11.3 –13 µm, paired actines 174– 285 –461 x 8 – 9.1 –12 µm, apical actines 66– 167 –234 x 8 – 8.9 –10 µm.

Distribution and ecology. Mozambique Channel, at 60 m depth.

Etymology. Named after Dr. Dirk Erpenbeck, München, Germany, in recognition of his great efforts to integrate molecules and morphology in the classification of the Porifera.

Remarks. The new species is assigned to Paraleucilla  on account of the skeletal zonation of an inarticulate subcortical skeleton formed by the apical actines of the cortical tetractines and the unpaired actines of giant triactines in the mid region of the choanosome, followed by a confused choanosomal and subatrial skeleton.

A regional species is Paraleucilla proteus (Dendy, 1913)  (originally as Leucilla  ). It has the same shape (although much smaller: only 7 mm high) as our new species. Differences are that almost all spicules, excepting the subcortical tetractines, are considerably smaller in size, notably the giant triactines do not seem to be represented, the apical actines of the atrial tetractines are much shorter, and there are no giant diactines (though smaller diactines are present). There are also no cortical small triactines. Dendy suggested that his small specimens were juveniles of the Australian species Leucilla australiensis ( Carter, 1886)  , but eventually Borojević et al. (2000) assigned Dendy’s species to Paraleucilla  .

A further geographically close species is Paraleucilla cucumis ( Haeckel, 1872)  (p. 205, as Leucandra  ) from Sri Lanka and South Australia, differing a.o. in the presence of subcortical and mid-region tetractines (the latter not present in our new species), and the absence of mid-region and atrial triactines, with as a consequence the absence of apical actines protruding into the atrial lumen. There is a small nomenclatorial problem, because Hackel (1872) divided his Leucandra cucumis  into two (?) varieties (‘spezifische Varietäten’), L.c. var. bassensis  and L.c. var. palcensis  . The difference was the virtual absence (bassensis) and presence (palcensis) of giant diactines. The difference was apparently considered trivial because neither Dendy (1892) and Dendy & Row (1913), nor Cavalcanti et al. (2014) make mention of these varieties. We formally need to indicate which one of the varieties is the nominotypical variety ( ICZN art. 47). In view of the redescription by Dendy (1892) it makes sense to consider the var. bassensis  as the typical variety, to be named Leucandra cucumis var. cucumis  , with the var. palcensis  as a junior synonym. The latter name would then be available if future research would result in distinction of an Indian Ocean species differing from the Bass Strait Paraleucilla cucumis  .

The new species is close to West Australian Paraleucilla princeps ( Row & Hôzawa, 1931)  (as Leucilla princeps  , p. 799, pl. 21 fig. 17, text-fig. 16), sharing tubular shape and most of the spicule complement. Also the sizes of the spicules conform rather closely. A major difference is the absence of giant triactines in the choanosomal skeleton. These spicules are a dominant feature of the present species, forming the skeletal structure of the peripheral inarticulate skeleton together with the apical actines of the subcortical tetractines. Row & Hôzawa do mention the presence of similar shaped smaller triactines but these only occur in the oscular region. Also not present are the small diactines.

Paraleucilla dalmatica Klautau et al. 2017  from the Mediterranean is similar in shape and skeletal structure, but spicule sizes differ significantly. Also, Brazilian P. incomposita Cavalcanti et al. 2014  is close in shape and structure but differs also in spicule sizes. Recently ( Chagas & Cavalcanti 2017), it was discovered that this species possesses choanosomal pentactines as a remarkable unique feature.

We obtained a 28S partial gene sequence for the holotype and compared it with a sequence downloaded from GenBank of Mediterranean Paraleucilla  spec. (supposedly the same as P. magna Klautau et al., 2004  ), which grouped together in our Phylogeny of Fig. 3 View Figure at a moderate bootstrap frequency (77%). From a separate investigation of a trimmed alignment of 295 sites obtained for the two sequences we found that P. erpenbecki  sp.nov. differs in 8 sites from the Mediterranean Paraleucilla  spec.


Universiteit van Amsterdam, Zoologisch Museum


Northern Arizona University














Paraleucilla erpenbecki

Van, Rob W. M. & De, Nicole J. 2018


P. erpenbecki

Van & De 2018


Paraleucilla dalmatica

Klautau et al. 2017


P. incomposita

Cavalcanti et al. 2014


P. magna

Klautau et al. 2004



Dendy 1892



Dendy 1892