Leucandra caribea, Cóndor-Luján & Louzada & Hajdu & Klautau, 2018
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publication ID |
https://doi.org/10.1093/zoolinnean/zlx082 |
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persistent identifier |
https://treatment.plazi.org/id/2B7987A4-FFA8-FFD0-A4CD-F616FD2AF928 |
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treatment provided by |
Plazi |
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scientific name |
Leucandra caribea |
| status |
sp. nov. |
LEUCANDRA CARIBEA View in CoL SP. NOV.
( FIGS 18–20 View Figure 18 View Figure 19 View Figure 20 ; TABLE 13)
Etymology: Named after its distribution in the Caribbean Sea.
Type locality: Tug Boat , Caracasbaai, Willemstadt, Curaçao .
Material examined: Holotype. UFRJPOR 6754, Tug Boat , Caracasbaai, Willemstadt, Curaçao (12°04′08.20″N, 68°51′44.40″W), 13.9 m depth, coll. B. Cóndor-Luján, 23 August 2011. GoogleMaps
Diagnosis: Leucandra with a sac-shaped body and leuconoid aquiferous system. The skeleton is mostly formed by triactines with some tetractines lining the choanosomal canals and atrial cavity. The choanosomal skeleton is composed of one category of triactines. Cortical trichoxeas are also present.
Colour: White in life ( Fig. 18A View Figure 18 ) and beige in ethanol ( Fig. 18B View Figure 18 ).
Morphology and anatomy: This species has a sac-shaped external morphology: it is wide at the base and becomes narrower near the osculum ( Fig. 18A View Figure 18 ). It measures 0.7 × 0.3 × 0.1 cm ( Fig. 18B View Figure 18 ). This sponge is quite smooth and compressible. Near the suboscular region there are short trichoxeas protruding through the surface ( Fig. 18C View Figure 18 ). The osculum is apical. It is supported by triactines, tetractines and has a discrete crown of trichoxeas ( Fig. 18D, E View Figure 18 ). The aquiferous system is leuconoid with subspherical choanocyte chambers ranging from 28.0 to 34.0 µm in diameter ( Fig. 18F View Figure 18 ). The diameter of the exhalant canals varies from 140.0 to 300.0 µm.
Skeleton: The skeleton is typical of the genus ( Fig. 19A View Figure 19 ). As mentioned before, the oscular margin has a differentiated skeleton. It is composed of T-shaped triactines and tetractines tangentially positioned and short trichoxeas perpendicular to the surface. The cortical skeleton is composed of tangential triactines ( Fig. 19B View Figure 19 ). The choanosomal skeleton does not have any special organization and it is formed by triactines of variable sizes (as shown in Figs 18F View Figure 18 , 19A View Figure 19 ). Several exhalant choanosomal canals were observed within this region. They are surrounded by tetractines with the apical actine projected inside them ( Fig. 19C View Figure 19 ). Some triactines lining the canals were also found ( Fig. 19D View Figure 19 ). No subatrial skeleton was observed. The atrial skeleton is formed by triactines ( Fig.19E View Figure 19 ) and rare tetractines ( Fig. 19F View Figure 19 ). The apical actine of the tetractines protrudes into the atrial cavity (arrow in Fig. 19F View Figure 19 ).
Spicules: Cortical triactines. Subregular or parasagittal. Actines are slightly conical with sharp tips. The paired actines are frequently curved and slightly longer than the unpaired one, which is always straight ( Fig. 20A View Figure 20 ). Size: 110.0–340.0/7.5– 16.3 µm (paired actine) and 105.0–325.0/7.5–16.3 µm (unpaired actine). Choanosomal triactines. Regular or subregular. Actines are conical with sharp tips ( Fig. 20B View Figure 20 ). They are the largest spicules in L. caribea sp. nov. Highly variable size: 370–960/25–75 µm. Triactines and tetractines of the canals. Sagittal. Actines are conical with sharp tips. The paired actines are curved, following the shape of the canals ( Fig. 20C, D View Figure 20 ). The apical actine of the tetractines is smooth and it is thinner than the basal actines (as shown in Fig. 19C View Figure 19 ). The size of the triactines is similar to that of the tetractines. Size of tetractines: 112.5–220/7.5– 12.5 µm (paired actine), 62.5–210.0/7.5–12.5 µm (unpaired actine) and 45.0–110.0/5.0–10 µm (apical actine). Atrial triactines (shown in Fig. 19E View Figure 19 ): Sagittal. Actines are conical with sharp tips. Compared to the cortical triactines, the atrial triactines are thinner and the angle formed by the paired actines is more open. Size: 132.3–253.8/8.1–13.5 µm (paired actine) and 164.7–253.8/5.4–13.5 µm (unpaired actine). Atrial tetractines. Sagittal. Actines are conical with sharp tips ( Fig. 20D View Figure 20 ). The apical actine is smooth. Size: 150.0–262.5/7.5–15.0 µm (paired actine), 162.0–297.0/8.1–16.2 µm (unpaired actine) and 35.0–132.5/7.5–12.5 µm (apical actine).
Ecology: This species was found underneath a coral boulder at 13.9 m depth. The basal region was attached to an algae (as shown in Fig. 18A, B View Figure 18 ).
Geographical distribution: Southern Caribbean (provisionally endemic to Curaçao, present study).
Taxonomic remarks: Among the species of Leucandra reported from the Caribbean Sea, namely L. crustacea ( Haeckel, 1872) , L. barbata ( Duchassaing & Michelotti, 1864) , L. curva ( Schuffner, 1877) , L. multiformis Poléjaeff, 1883 , L. rudifera Poléjaeff, 1883 , and L. typica ( Poléjaeff, 1883) ( Van Soest et al., 2017) , only L. typica possesses a similar skeletal composition as that of L. caribea sp. nov. The skeletons of the other Caribbean species include cortical tetractines ( L. crustacea and L. curva ), diactines ( L. barbata , L. multiformis and L. rudifera ) and atrial grapnel spicules (also in L. rudifera ), which are spicule categories absent in L. caribea sp. nov.
Leucandra caribea sp. nov. can be differentiated from L. typica as the former species possesses an atrial skeleton mainly composed of triactines and few tetractines, whereas in the latter species, triactines and tetractines are in the same proportion (or at least, Poléjaeff did not indicate the opposite). Besides, in the new species, the choanosomal canals are lined by tetractines and triactines and in L. typica they are only lined by tetractines. In L. typica , trichoxeas (<300.0/1.0 µm) are scattered in the choanosome and spindle-shaped microdiactines (100.0/4.0 µm) are concentrated in the suboscular region, while in L. caribea sp. nov., trichoxeas (>100.0/1.2 µm) were found only in the suboscular region.
Among the other species of Leucandra with skeletal composition and external morphology comparable to that of L. caribea sp. nov, L. falakra Klautau, ImeŠek, Azevedo, PleŠe, Nikolić & Ćetković, 2016 from the Adriactic Sea is the one that most resembles the new species. Nonetheless, they have some important differences. The choanosomal skeleton of the Curaçaoan species is composed of one single type of triactine (370.0–960.0/25.0–75.0 µm) while in the Adriatic species, it is composed of small (paired actine: 94.5–180.9/8.1–13.5 µm and unpaired actine: 70.0–143.1/8.1–16.2 µm) and giant triactines (342.0– 1047.6/48.6–118.8 µm). Additionally, although almost all the spicule categories have similar dimensions ( Table 13), the unpaired actine of the atrial tetractines is shorter in L. falakra (59.4–126.9 µm) than in the new species (162.0–297.0 µm).
GENUS LEUCANDRILLA BOROJEVIC, BOURY-ESNAULT & VACELET, 2000 View in CoL
Type species: Leucilla wasinensis Jenkin, 1908 .
Diagnosis: ‘ Grantiidae with leuconoid organization. In addition to triactines the cortex contains tetractines, with the apical actines turned into the choanoderm. The articulated choanoskeleton is supported by subatrial triactine spicules, and numerous rows of choanosomal triactines and/or tetractines, with apical actines of cortical tetractines in the distal region’ ( Borojevic et al., 2000).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Leucandra caribea
| Cóndor-Luján, Báslavi, Louzada, Taynara, Hajdu, Eduardo & Klautau, Michelle 2018 |
LEUCANDRILLA
| BOROJEVIC, BOURY-ESNAULT & VACELET 2000 |