Galilia petricola, Komai, Tomoyuki & Tsuchida, Shinji, 2014
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publication ID |
https://doi.org/ 10.11646/zootaxa.3764.3.3 |
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publication LSID |
lsid:zoobank.org:pub:F1B0E174-89C5-4A9E-B7DA-C5E27AF624D3 |
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DOI |
https://doi.org/10.5281/zenodo.6132367 |
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persistent identifier |
https://treatment.plazi.org/id/03EB595D-FF9D-7578-FF66-F8EA4D87FC6A |
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treatment provided by |
Plazi |
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scientific name |
Galilia petricola |
| status |
sp. nov. |
Galilia petricola View in CoL n. sp.
( Figs. 18–21 View FIGURE 18 View FIGURE 19 View FIGURE 20 View FIGURE 21 , 30 View FIGURE 30 C)
Material examined. RV “Natsushima”, NT10-13 cruise, ROV “Hyper-Dolphin”, dive #1165, Northeast Nikko Seamount, 31 July 2010, three of four specimens collected from four points (23°06.712’N, 142°21.848’E, 562 m; 23°06.766’N, 142°21.934’E, 551 m; 23°06.617’N, 142°21.836’E, 595 m; 23°06.639’N, 142°21.848’E, 576 m) were examined: holotype, male (23.8 × 25.2 mm), NSMT-Cr 22721; paratypes, 1 male (22.4 × 23.7 mm), 1 ovigerous female (22.2 × 25.0 mm), JAMSTEC 0 81532.
Description. Males. Carapace ( Figs. 18 View FIGURE 18 , 19 View FIGURE 19 A, B, C) rounded, slightly broader than long; regions well demarcated, grooves between regions distinct, especially branchial ones; surface covered with numerous small pearliform or fungiform granules and numerous bumps; hepatic region with 2 rounded tubercles, lower tubercle larger than upper one; cardiac region prominently swollen, with low tubercle at top; intestinal region with 2 large rounded tubercles, directed posteriorly; branchial region with 16 or 17 small tubercles. Front ( Fig. 19 View FIGURE 19 E) distinctly bilobed, lobes low, separated by broad V-shaped cleft, each lobe triangular, tip rounded, surface covered with numerous small granules. Orbit with 3 fissures; inner orbital lobe clearly separated from lateral angle of front. Suborbital region with deep groove.
Epistome ( Fig. 19 View FIGURE 19 E) very short; anteromedian part of buccal cavern roundly triangular.
Eye ( Fig. 19 View FIGURE 19 A, B, E) small; eyestalk strongly constricted at midlength.
Basal antennular article filling lower half of fossa when retracted ( Fig. 19 View FIGURE 19 E); distal 2 articles of antennular peduncle and flagella retracted slightly obliquely in upper half of fossa. Antennal peduncle fully visible in anterior view, extending into orbit; flagellum filiform.
Mouthparts not dissected. Third maxilliped ( Figs. 19 View FIGURE 19 B, 21A) covered with pearliform or fungiform granules of various sizes on outer surface. Ischium with sharp, entire mesial margin. Merus subtriangular, slightly bent dorsally in situ, about half length of ischium measured along mesial margin; inner face mesially with distinct excavation accommodating carpus to dactylus. Distal 3 segments tapering distally. Exopod slightly narrower than endopod, slightly tapering to rounded distal margin, without conspicuous tooth on lateral margin, proximolateral angle gently rounded; inner surface deeply grooved medially, with strong keel mesially.
Chelipeds ( Figs. 18 View FIGURE 18 , 20 View FIGURE 20 A) less than 2 times of carapace length, entirely covered with pearliform or fungiform granules on all segments, including fingers (granules on fingers fine, minute). Merus subcylindrical, not curved. Carpus about half length of palm, slightly widened distally, without ridges on external surface. Palm slightly inflated, slightly tapering distally; dorsal surface slightly depressed in distal half. Fingers subequal in length to palm, almost straight, cutting edges with row of tiny, blunt or subacute denticles; fixed finger with 2 weak granular ridges along midline on external and internal surfaces, ventral margin sharply keeled; dactylus also with 2 weak granular ridges on external and internal surfaces and distinct dorsal ridge.
Ambulatory legs ( Fig. 18 View FIGURE 18 ) relatively short, surfaces covered with closely packed granules; length decreasing gradually from first to fourth legs. Dactyli subequal to or slightly shorter than propodi, gently arcuate, terminating in sharp corneous unguis.
Thoracic sternum ( Fig. 19 View FIGURE 19 D, F) covered with pearliform or fungiform granules (lateral granules smaller and more closely spaced than mesial ones; sternite 2 medially produced in small triangular process; sternites 3 and 4 swollen, raised; sternites 5–7 medially depressed, appearing sunken; sterno-abdominal cavity narrow, very deep.
Pleon ( Fig. 19 View FIGURE 19 B, D, F) with third to sixth pleomeres fused, shallow transverse grooves, suggesting divisions between third, fourth and fifth pleomeres, seen; distal border of sixth pleomere elevated, with distinct median process directed ventrally. Telson ( Figs. 19 View FIGURE 19 F, 21B) slender, noticeably elongate, about two-thirds of fused third to sixth somites in length, tongue-shaped, strongly curved in proximal half as it fitting into sterno-abdominal cavity of swollen sternites 4 and 5 ( Fig. 19 View FIGURE 19 B).
First gonopod ( Fig. 21 View FIGURE 21 C, D) slender, gradually tapering distally, reaching to midlength of thoracic sternite 4; distal third curving towards sternum at approximately 70° angle, with small terminal pore ( Fig. 21 View FIGURE 21 E); internal surface with scattered microscopic setae ( Fig. 21 View FIGURE 21 F); tip blunt. Second gonopod ( Fig. 21 View FIGURE 21 G–I) with distal segment divided in 2 parts, distal part lance-shaped, subacutely pointed; proximal part gently curved ventrally, strongly compressed laterally, with prominent setose lobe proximolaterally.
Female. Generally similar to male. Cheliped merus proportionally slightly shorter than that of male. Sternoabdominal cavity deeply excavate; valvae each with prominent flange. Abdomen ( Fig. 20 View FIGURE 20 B) dome-shaped, third to six pleomeres fused though shallow transverse grooves suggesting division of these pleomeres still discernible; surfaces covered with rounded, flattened granules. Telson ( Fig. 21 View FIGURE 21 J) subtriangular with distinctly concave lateral margins; tip rounded; surface covered with flattened granules.
Coloration in life. Carapace generally orange; chelipeds and ambulatory legs banded with orange and white.
Distribution. Known only from Northeast Nikko Seamount, 562– 595 m.
Ecology. The collected individuals were found on rock surfaces or rubbles ( Fig. 29 View FIGURE 29 C).
Remarks. The new species is very similar to the type species of the genus, Galilia narusei Ng & Richer de Forges, 2007 in the general structure of the carapace, thoracic sternum, abdomen, telson, and gonopods. Nevertheless, G. petricola n. sp. is distinguished from G. narusei by less prominent tubercles on the branchial regions of the carapace and the different structure of the first gonopod. In the new species, the distal one-third of the first gonopod curves toward the sternum at approximately 70° angle, rather than 90° angle in G. narusei ; the distal part is stouter with the tip more narrowly pointed in G. petricola n. sp. than in G. narusei (cf. Ng & Richer de Forges 2007: Fig. 4 View FIGURE 4 G, H).
In their original description of G. narusei, Ng & Richer de Forges (2007: 18) stated that “Basal antennular article large, completely sealing fossa when retracted.” However, their figure (Ng & Richer de Forges 2007: fig. 2C, E) clearly shows the distal articles of the antennular peduncle are retracted in the upper surface of the fossa and are not concealed by the basal article. Consequently, we assume that the interpretation of the structure of the antennule and antennular fossa by Ng & Richer de Forges (2007) was not correct. In the present new species, the basal antennular article fills only the lower half of the antennular fossa.
Etymology. Combination of the Latin petra (= rock) and colus (= living), in reference to the habitat of this new species.
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.