Corresponding author: Andrew M. Hosie (
Academic editor: Kai Horst George
A new species of sponge-inhabiting barnacle,
Hosie AM, Fromont J, Munyard K, Jones DS (2019) Description of a new species of
Barnacles of the genus
The
This study describes a new species
Prior to dissection, the designated holotype was scanned via μCT using a Zeiss Versa XRM-520 X-ray microscope at the Centre for Microscopy, Characterisation and Analysis at the University of Western Australia. Processing of the resulting data followed the methods described in
For direct morphological examination of barnacle shell plates and arthropodal characters, the body and associated soft tissues were removed from the shell. The remnants of the barnacle tissue and host sponge on the surfaces of the parietes, scutum and tergum were removed using forceps. The shell was then immersed in 2% bleach for ~2 h to completely digest the organic tissue and subsequently rinsed in purified water. Any remaining debris or contaminants were then removed by cleaning in an ultrasonic cleaner for less than 20 s for shell plates and 5 s for arthropodal parts. The specimens were examined under a Leica M205 C (Leica, Germany) stereomicroscope and digital photographs produced with a Leica DMC4500. For scanning electron microscopy, specimens were first dehydrated in an ethanol series (70%, 80%, 90%, 100%, 5 minutes each) then transferred to hexamethyldisilazane for 10 min. Excess liquid was then removed with an eye-dropper and specimens were left to dry in a fume hood for 30 min. The dissected specimens were mounted on stubs, sputter coated with gold, and observed using a Hitachi TM3030 tabletop SEM. All images were processed using Adobe Photoshop CS3.
Adductor or depressor muscle tissues were subsampled from specimens, and genomic DNA was extracted using either a Bioline Isolate II or Qiagen DNeasy extraction kit following the manufacturers’ instructions. Partial fragments of the cytochrome c oxidase I gene were amplified using the primers dgLCO1490 5'-GGTCAACAAATCATAAAGAYATYGG-3' and dgHCO2198 5'-GGTCAACAAATCATAAAGAYATYGG-3' (Meyer et al. 2003) in a 25 µL reaction volume consisting of 1 unit MyTaq DNA polymerase, 1× MyTaq PCR buffer, 0.5 µL of each primer, and 2 µL template. The following polymerase chain reaction conditions were used: 2 min at 95 °C for initial denaturing, then 35 cycles of 30 s at 95 °C, 30 s at 46 °C, 45 s at 72 °C, and a final extension for 7 min at 72 °C. The resulting amplicons were sequenced by the Australian Genome Research Facility, Perth, using the same primers. The sequences were assembled and trimmed using Geneious Prime and submitted to GenBank (Table
Accession details for COI sequences of
Specimen catalogue | GenBank # |
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WAM C66803 |
|
WAM C71853 |
|
WAM C71881 |
|
Specimens of both barnacles and sponges are housed at the Western Australian Museum, Perth (WAM) and South Australian Museum, Adelaide (SAMA).
Parietes solid, unornamented, weakly articulated, basis membranous. Rostrum scoop or boat-shaped, often elongate relative to other parietes. Tergum with spur furrow open. Cirrus IV with erect spines, with or without recurved teeth on anterior ramus.
With the addition of the below described species, there are now 10 species included within
The remaining
Shell wall robust, cylindrical, growth ridges weak; orifice toothed, large; rostrum basal margin broadly rounded, extending below basal plane of remaining parietes. Tergum narrow, beaked, spur narrow, separated from basiscutal angle by half its own width; scutum with faint, external longitudinal striations; basitergal angle broadly rounded. Cirri III and IV with row of strong, erect spines on anterodistal margin of anterior ramus; cirrus IV pedicel without erect spines; cirri IV and V with row of stout spines on posterior margin of anterior ramus basal segment.
All shell plates, prosoma, and internal organs stained purple
Interactive 3D, μCT derived volume reconstruction of
Scutum (Fig.
Tergum (Fig.
Labrum (Fig.
Mandibular palp (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
Cirrus I (Fig.
Cirrus II (Fig.
Cirrus III (Fig.
Cirrus IV (Fig.
Cirrus V (Fig.
Cirrus VI (Fig.
Cirral segment counts as follows (anterior ramus, posterior ramus):
|
|
|
|
|
|
|
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WAM C66803 | L | 21, 9 | 9, 11 | 17, 13 | 27, 30 | 34, 32 | 33, 33 |
R | 20, 9 | 11, 9 | 17, 14 | 30, 30 | 32, 34 | 36, 34 |
Penis longer than CVI, annulated, sparsely setose along length; basidorsal point (Fig.
Southern Australia, from Perth to Adelaide.
From Greek
Only a single sequence, identified as
The degree of elongation and curvature of the rostrum is variable in
While
No other barnacle species were found inhabiting any of the 15
Host specificity of
1 | Cirrus IV anterior ramus bearing recurved teeth and erect spines |
|
– | Cirrus IV anterior ramus bearing only erect spines |
|
2 | Rostrum much longer than other parietes |
|
– | Rostrum approximately as long as other parietes |
|
3 | Radii absent |
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– | Radii present |
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4 | Scutum with radius-like ledge on occludent margin |
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– | Scutum occludent margin normal, lacking ledge |
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5 | Parietes costate |
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– | Parietes not costate |
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6 | Basal margin of all parietes rounded; tergal articular ridge low, articular groove open |
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– | Basal margin of laterals more or less straight; tergal articular ridge overhanging articular groove |
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7 | Radii broad, conspicuous; tergal spur narrow, longer than wide, cirrus IV pedicel without erect spines on anterodistal margins |
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– | Radii absent or very narrow, tergal spur wider than long, cirrus IV pedicel with erect spines on anterodistal margins |
|
8 | Rostrum with median furrow, elongated basal portion tapering, very narrow |
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– | Rostrum without median furrow, basal portion wedge-shaped |
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9 | Basal membrane with spine-like processes |
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– | Basal membrane without spine-like processes |
|
This study was funded in part by the Australian Biological Resources Study Grant #RF213-25, Gorgon Barrow Island Net Conservation Benefits Fund, and the Australian Government Research Training Program. Nikolai Tatarnic (WAM) carried out the CT scans at Australian Microscopy & Microanalysis Research Facility at the Centre for Microscopy, Characterisation & Analysis, The University of Western Australia, a facility funded by the University, State, and Commonwealth Governments. We thank Andrea Crowther (SAM) for hosting visits to the collections by AMH and for making specimens from South Australia available for study, Ana Hara and Oliver Gomez (both WAM) for assistance with specimen handling and processing in the lab and field, and Michelle Condy, Linette Umbrello, and Kara Layton for their work undertaking extractions and PCRs in the WAM Molecular Systematics Unit. The comments and suggestions on the manuscript by Meng-Chen Yu, as reviewer, were also greatly appreciated.