Leucosolenia qingdaoensis, Chu & Gong & Li, 2020
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publication ID |
https://dx.doi.org/10.3897/zookeys.906.47164 |
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publication LSID |
lsid:zoobank.org:pub:DE8D65F1-1739-4377-8BC4-E42F84E77B08 |
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persistent identifier |
https://treatment.plazi.org/id/F0C1D83E-3940-4D4C-B0BB-60A379ED507D |
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taxon LSID |
lsid:zoobank.org:act:F0C1D83E-3940-4D4C-B0BB-60A379ED507D |
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treatment provided by |
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scientific name |
Leucosolenia qingdaoensis |
| status |
sp. nov. |
Leucosolenia qingdaoensis sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 ; Tables 1, 2
Type material.
Holotype: MBM181606, scallop-breeding pond on southeastern Shandong Peninsula, China, June 1988, 0-0.3 m depth, collected by Shue Li, 35°58'N, 120°11'E. Paratype: MBM181476, Zhonggang, Qingdao, China, 7 June 1984, 0-0.6 m depth, 36°06'N, 120°21'E.
Type locality.
Qingdao, Yellow Sea.
Etymology.
The name is derived from the type locality, Qingdao, China.
Description.
The sponge is arborescent, consisting of many thin-walled tubes, which are copiously ramified but never anastomosed. The sponge occurs as growth form. The oscula are terminal on erect tubes. The color of the sponge is white after being preserved in alcohol and in vivo. The external walls of the tubes are hairy, with diactines protruding at right or oblique angles from the body; the surface is minutely hispid, and the consistency is soft and fragile. The holotype measures 21.32 × 3.38 mm (height × width). The wall of the sponge body is very thin, and there is no fully developed inhalant system, the gap between the skeleton and the cell on the wall arrange evenly (Fig. 2F View Figure 2 ); only a small amount of cells is distributed on the thin sponge skeleton (Fig. 2C-F View Figure 2 ), which is a typical asconoid feature. All internal cavities of the sponge are lined by choanocytes.
Skeletal arrangement.
The skeleton consists of multifarious diactines, sagittal triactines of two types, sagittal tetractines with bent apical actines and triactine-like basal actines; together these form the wall of the ascon-type sponge body.
In the apical osculum (Fig. 2C, E View Figure 2 ), there are paired actines of triactines and tetractines, some additional tangential diactines, together forming a clear line dividing the apical oscula, and some radial diactines projecting beyond the apical osculum with different length.
In the sponge body (Fig. 2C, E View Figure 2 ), the triactines and tetractines are regularly arranged, their paired actines are parallel to the apical oscula, and the unpaired actines point downward, with slight folding allowed, but never overlapping; in contrast to the triactines and tetractines, the diactines are arranged more irregularly but generally point downward.
In the root-like structures (Fig. 2D, F View Figure 2 ), the arrangement of triactines and tetractines is the same as that in the body, but the arrangement of diactines is different; most of them tangentially project beyond the surface, which results in the surface having a slightly hispid appearance.
By observing the sponge tissue taken from different parts, it is clear that as the diameter of the tubes decreases, the contents of small diactines and small triactines increase. This observation can suggest that in the growth zone spiculogenesis is more intense.
Spicules.
Diactines. There is only one type of diactine (Fig. 3A1-3 View Figure 3 ), though the diactines vary in size and shape, their width varies from 24 µm to 61 µm, the length of diactines vary from 43 µm to 421 µm but half of the diactines present a length of 200-300 µm (Fig. 4 View Figure 4 ). The shapes of the diactines are straight or slightly curved in different directions. The variation in Leucosolenia is very common and considerable.
Triactines. Two types of triactines are present, with actines straight or undulated. Their ends are generally sharp or asymmetrical (Fig. 3B1 View Figure 3 - 2 View Figure 2 ). The paired actines are slightly curved. Some deformations are present.
Type 1: triactines with paired actines longer than unpaired actines (Fig. 3B1 View Figure 3 ): unpaired actines 42-105 × 3-5 µm; paired actines 63-105 × 3-5 µm.
Type 2: triactines with unpaired actines longer than paired ones (Fig. 3B2 View Figure 3 ): unpaired actines 76-129 × 3-4 µm; paired actines 60-104 × 3-4 µm.
Tetractines. A relatively small number of tetractines are observed, approximately 10 per 100 spicules, with straight and fusiform actines (Fig. 3C1 View Figure 3 - 2 View Figure 2 ). The tetractines are similar to triactines but with the addition of apical actines, the apical actines are fairly stout and short, sharply pointed and curved: unpaired actines 93-119 × 2-5 µm; paired actines 50-93 × 2-5 µm; apical actines 11-29 × 2-5 µm.
Remarks.
Three species described by Tanita ( L. minuta , L. pyriformis , and L. serica ) exhibit only regular (equiangular and equiradiate) spicules. This characteristic does not fit the description of Leucosolenia , L. qingdaoensis sp. nov. can be easily differentiated from the 12 species of Leucosolenia reported from the Pacific Ocean. The skeletal compositions of these species are shown in Table 1 View Table 1 .
The new species exhibits one type of diactine. In L. ventosa and L. rosea , there is no record of diactines, and in L. mollis and L. nautilia , there are two types of diactines. The triactines of L. ventosa are 2-8 times thicker than those in the new species; the triactines of L. rosea are 10-35 times thicker than in the new species; and L. mollis only has one type of triactine and all rays being nearly equally thick. The diactines of L. nautilia are extremely large, with a length of 1 mm and a thickness of 20 µm ( Laubenfels 1932), while in the new species the diactines are less than 8 µm thick. Laubenfels (1932) gave few details on the actines, but L. nautilia differs from the new species by having only one type of triactine.
The difference between L. albatrossi and the new species is obvious. The diactines of L. albatrossi are club-shaped, while the diactines of the new species are spindle-shaped.
The sagittal triactines of the new species distinguish it from L. macquariensis , L. tenera , and L. eleanor . The new species have two types of sagittal triactines, while L. macquariensis and L. tenera only have one type of sagittal triactine, with rays of approximately equal length. Leucosolenia eleanor have both sagittal and regular triactines.
The new species, with slender and long diactines, the longest diactines 5 times longer than those of L. feuerlandica , is distinct from that species. Additionally, the triactines of the new species are sagittal, and the actines straight or undulated. However, the triactines of L. feuerlandica are pseudoderm sagittal and are tripod-shaped.
Leucosolenia echinata , L. lucasi , and L. qingdaoensis sp. nov. have many features in common, including their body shape, colour in alcohol, general arrangement, shape of diactines, and apical ray, but they show important differences in the shape of their triactines. The new species has two types of triactines; L. lucasi and L. echinata only have one type of triactine. The triactines of L. lucasi are sagittal, but the three angles are roughly equal; the triactines of L. echinata are generally regular, and frequently slightly sagittal, with the oral angle largest and the basal ray longest.
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