Leucandra mozambiquensis

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160: 100-103

publication ID

https://doi.org/10.11646/zootaxa.4426.1.1

publication LSID

lsid:zoobank.org:pub:18929E20-5296-4458-8A8A-4F5316A290FD

persistent identifier

http://treatment.plazi.org/id/386CC616-DC11-A557-FF67-8BBAFE68FD54

treatment provided by

Plazi

scientific name

Leucandra mozambiquensis
status

sp.nov.

Leucandra mozambiquensis  sp.nov.

Figs 60a–f View Figure , 61a–e View Figure

Material examined. Holotype, ZMAAbout ZMA Por. 22408a, Mozambique Channel, between Mozambique and Madagascar, E of Juan de Nova Island, 17.2817°S 43.1567°E, depth 60 m, dredged, Pelagia Around Africa Exped.II, leg 6, field nr. 20 ASCAbout ASC 10, 1 April 2001.

Description. Irregular cup-shaped hollow mass ( Fig. 60a View Figure ) with undulating unequal lumpy walls, size 5 x 5 x 4 cm, walls approximately 1 cm thick. Color in alcohol pale brownish to dirty white. Surface rough. Inner surface of the atrial ‘hollow’ with a few oscular openings of 3–4 mm diameter. Consistency firm but fragile.

Aquiferous system. Leuconoid.

Skeleton. ( Figs 60b–f View Figure ) A cross section ( Fig. 60b View Figure ) shows a confused mass of spicules separated by a clearly developed cortical skeleton ( Figs 60c–d View Figure ) of smaller, mostly sagittal ‘oxhorn’ triactines and a clearly developed atrial skeleton ( Figs 60e–f View Figure ) of atrial tetractines. The choanosomal mass of spicules consists of giant triactines and smaller triactines. Near the atrial skeleton there are also sagittal subatrial tetractines recognizable by unpaired actine of length equal to the paired actines (whereas the atrial tetractines have shorter unpaired actines).

Spicules. ( Figs 61a–e View Figure ) Giant triactines, smaller triactines, atrial and subatrial tetractines.

Giant triactines ( Figs 61a View Figure ) of the choanosomal region, sagittal, usually with unpaired actine shorter than the paired actines, occasionally irregular with actines all of different lengths, actines relatively thin compared to other Leucandra  species, 471– 903 – 1322 x 30 – 52.9 –72 µm.

Smaller triactines ( Figs 61b View Figure ) of the surface and the choanosome, not clearly differentiated, but either regular or more often ‘oxhorn’-like sagittal with curved and often slightly wobbly paired actines; unpaired actines 184– 258 –346 x 10 – 15.6 –26, paired actines 191– 348 –574 x 10 – 15.9 –34 µm.

Tetractines ( Figs 61c–d View Figure ), sagittal, with straight unpaired actines, straight or slightly curved paired actines, and straight or slightly curved apical actines, divisible into subatrially located tetractines with unpaired actines approximately as long as the paired actines, and proper atrial tetractines with unpaired actines clearly shorter than the paired actines.

Subatrial tetractines ( Fig. 61c View Figure ) with unpaired actines measuring 174– 221 –247 x 8 – 11.8 –15 µm, paired actines 187– 239 –298 x 11 – 12.6 –15 µm, apical actines 40– 55.6 – 73 x 5 – 6.7 –10 µm.

Atrial tetractines ( Figs 61d View Figure ) with unpaired actines 84– 108 –151 x 5 – 8.8 –12 µm, paired actines 210– 245 –289 x 6 – 9.2 –15 µm, apical actines 41– 62 – 92 x 5 – 6.3 –7 µm.

Distribution and ecology. Mozambique Channel, on continental platform of NW Madagascar, depth 60 m.

Etymology. Named after the type locality.

Remarks. By the absence of giant diactines, this elaborate species stands out among Leucandra  species in the region. Only the above described L. pilula  sp.nov. shares the lack of giant diactines, but that species has radically

different morphology and also the spicules have different dimensions (cf. above). The new species shows morphological similarities to NE Australian Leucandra nicolae Wörheide & Hooper, 2003  , which also lacks giant diactines and has elaborate shape, but that species has microdiactines lining the choanocyte chambers, which are not present here. The giant triactines of L. nicolae  have shorter and thicker actines than the present material.

The tetractines of the subatrial region indicate a possible membership of the new species of the genus Leucandrilla  (cf. below), because subcortical spicules in that genus include tetractines. However, the presence of the long-shafted tetractines in the present material is always close to the atrial skeleton, not in the subcortical region, and they are probably to be considered part of the atrial skeleton.

We obtained a partial 28S sequence of the holotype. In our Calcaronea phylogeny ( Fig. 3 View Figure ), the new species grouped together with L. pilula  sp.nov. and L. nicolae  at a modest bootstrap value (see also above under Remarks of L. pilula  sp.nov.). The relationship with the other two species in the clade is not close.

The nearest group to Leucandra  in our phylogeny ( Fig. 3 View Figure ) is Paraleucilla  , currently assigned to the family Amphoriscidae  . The general lack of sufficient 28S sequences of Calcaronea makes this position debatable. A separate inspection of the trimmed alignment of sequences of the clade of the three Leucandra  species and the two Paraleucilla  species (length 423 sites) showed 37 non-conserved sites indicating a large difference between the genera (see also below).

ZMA

Universiteit van Amsterdam, Zoologisch Museum

ASC

Northern Arizona University