Parasesarma aurifrons, Li & Shih & Ng, 2019
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publication ID |
https://doi.org/ 10.6620/ZS.2019.58-40 |
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persistent identifier |
https://treatment.plazi.org/id/9C3F8793-FFFA-FFEB-FF45-FB5E0D162BE0 |
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treatment provided by |
Felipe |
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scientific name |
Parasesarma aurifrons |
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Genus Parasesarma De Man, 1895 View in CoL
Parasesarma aurifrons n. sp. ( Figs. 1A, B View Fig , 2A–D View Fig , 3 View Fig , 4 View Fig , 11A View Fig ) urn:lsid:zoobank.org:act:DA0C9021-6010-41B8-9CAB-4EA210F38FC0
Parasesarma aff. ungulatum – Li and Chiu 2013: 81.
Material examined: Holotype: ò (10.4 × 8.5 mm) (NCHUZOOL 15602), Gangkou River (= R.) estuary (21°59'16.1"N 120°50'29.7"E), Hengchun, Pingtung, Taiwan, coll. J.-J. Li, 25 Mar. 2016 GoogleMaps . Paratypes: Taiwan: Gangkou R. estuary, Hengchun, Pingtung: 2 ññ (10.4 × 8.2 mm, 13.6 × 11.0 mm) (NCHUZOOL 15611), coll. J.-J. Li, 7 Jun. 2012; 1 ò (12.7 × 10.2 mm), 1 ñ (12.3 × 10.4 mm) (NCHUZOOL 15605), coll. J.-J. Li, 11 Apr. 2015; 1 ò (14.2 × 10.9 mm) ( ZRC 2019.1075), coll. J.-J. Li, 17 May 2015; 1 ò (12.4 × 10.2 mm) (NCHUZOOL 15610), coll. J.-J. Li, 15 Jul. 2015; 1 ò (10.1 × 8.2 mm) ( ZRC 2019.0819), coll. J.-J. Li, 18 Aug. 2015; 2 òò (11.2 × 8.8 mm, 12.1 × 10.3 mm) (NCHUZOOL 15603), coll. J.-J. Li, 1 May 2016; 1 ñ (12.4 × 10.0 mm) (NCHUZOOL 15606), coll. J.-J. Li, 24 May 2016; 2 ññ (13.6 × 11.1 mm, 13.8 × 11.2 mm), 2 ovig. ññ (11.1 × 9.3 mm, 14.0 × 11.6 mm) (NCHUZOOL 15609), coll. J.-J. Li, 15 Jun. 2016; 3 òò (11.0–12.4 × 9.6–10.4 mm) (NCHUZOOL 15607), coll. J.-J. Li, 20 Jun. 2016; 1 ò (12.0 × 10.0 mm) (NCHUZOOL 15608), coll. J.-J. Li, 24 Jul. 2016; 9 òò (9.8–11.1 × 8.2–9.5 mm), 4 ññ (10.7–11.5 × 8.4–9.1 mm), 1 ovig. ñ (11.8 × 10.2) ( ZRC 2019.0822), coll. J.-J. Li, 11 Jul. 2017; 4 òò (8.4–13.2 × 7.0– 10.6 mm) (NCHUZOOL 15604), coll. J.-J. Li, 15 Jun. 2019. Baoli R. estuary (22°03'27.1"N 120°42'28.4"E), Hengchun, Pingtung: 1 ò (12.4 × 11.0 mm) ( ZRC 2019.0823), coll. J.-J. Li, 6 Aug. 2015; 1 ò (12.6 × 10.6 mm) (NCHUZOOL 15533), coll. P.-Y. Hsu et al., 4 Sep. 2017; 1 ovig. ñ (11.0 × 9.2 mm) (NCHUZOOL 15534), coll. P.-Y. Hsu et al., 18 Mar. 2018.
Other material: Taiwan: Gangkou R. estuary, Hengchun, Pingtung: 1 ñ (10.6 × 8.5 mm) (NCHUZOOL 15616), coll. J.-J. Li, 27 Jun. 2012; 2 òò (10.1 × 8.9 mm, 10.9 × 9.2 mm) (NCHUZOOL 15615), coll. J.-J. Li, 18 May 2015; 1 ñ (11.4 × 9.6 mm) (NCHUZOOL 15618), coll. J.-J. Li, 1 Jun. 2015; 1 ò (11.3 × 9.2 mm), 1 ñ (9.9 × 8.1 mm) (NCHUZOOL 15621), coll. J.-J. Li, 5 Aug. 2015; 1 ò (11.7 × 9.7 mm) (NCHUZOOL 15619), coll. J.-J. Li, 15 Aug. 2015; 1 ò (11.0 × 9.0 mm) (NCHUZOOL 15620), coll. J.-J. Li, 24 Sep. 2015; 2 òò (10.7 × 8.9 mm, 11.4 × 9.5 mm) (NCHUZOOL 15617), coll. J.-J. Li, 7 Jul. 2016; 2 òò (10.1 × 6.2 mm, 10.8 × 6.2 mm) (NCHUZOOL 15612), coll. J.-J. Li, 2 Dec. 2016; 1 ñ (11.5 × 9.4 mm) (NCHUZOOL 15613), coll. J.-J. Li, 17 Jul. 2017; 1 ò (11.0 × 9.1 mm) (NCHUZOOL 15614), coll. J.-J. Li, 11 Aug. 2017. Philippines: 1 ovig. ñ (11.6 × 9.7 mm) (NCHUZOOL 15622), Kawasan, Cebu, coll. J.-J. Li, 6 Sep. 2018.
Comparative material: Parasesarma ungulatum (H. Milne Edwards, 1853) : 2 òò (14.3 × 11.0 mm, 19.6 × 15.6 mm) ( ZRC 1999.0566), Chonburi, eastern Thailand, coll. P. K. L. Ng, 29 Sep. 1998. Parasesarma obliquefrons ( Rathbun, 1924) : holotype ò (12.8 × 11.3 mm) ( USNM 45913a), in fresh water, Pago Pago, Samoa, coll. 28 Jul. 1902; 4 òò, 9 ññ (5 ovig.) ( USNM 45913b), same data as holotype.
Diagnosis: Carapace ( Figs. 1A View Fig , 2A View Fig , 3A View Fig , 4A View Fig ) almost squarish in dorsal view, 1.2 times broader than long; front ( Fig. 3B View Fig ) with margin straight in dorsal view; external orbital tooth triangular, directed obliquely outwards, representing point of greatest width of carapace; lateral margins straight, slightly converging posteriorly, without trace of tooth or indentation behind external orbital tooth. Male chela ( Figs. 3C, D View Fig , 4B– D View Fig ) with 2 transverse pectinate crests on upper surface; distal crest composed of 14–19 high corneous teeth; second crest well developed, shorter than proximal crest, with 8 or 9 corneous teeth; dactylus with 12–15 asymmetrical tubercles on upper surface, proximal 4 to 5 tubercles large, remaining tubercles smaller, distal tubercle almost indiscernible. Ambulatory legs ( Figs. 1A View Fig , 2A View Fig , 3A View Fig ) slender; P3 and P4 about 1.5 times carapace width; merus of P3 2.1 times as long as broad; upper margin with acute subdistal spine; propodus of P3 2.4 times as long as broad; dactylus of P3 0.8 times length of propodus. Male pleon ( Figs. 1B View Fig , 11A View Fig ) relatively broad, telson semicircular, somite 6 almost twice as long as wide, lateral margins slightly convex. G1 ( Figs. 3E, F View Fig , 4E View Fig ) straight, relatively stout; apical process very short, corneous part short, ending in truncated tip; setae long, simple, originating at base of apical process. Vulva ( Figs. 3G View Fig , 4F View Fig ) near anterior edge of sternite 5, with central operculum, oval shaped.
Description of holotype male: Carapace ( Fig. 3A View Fig ) almost squarish in dorsal view, 1.2 times broader than long; regions well defined, separated by shallow grooves; upper surface laterally with oblique striae, otherwise smooth; postfrontal region well delimited, separated into 4 lobes by shallow but distinct grooves; median lobes almost as wide as lateral lobes; front ( Figs. 3B View Fig , 4A View Fig ) deflexed downwards, margin straight in dorsal view; supraorbital margin gently convex; external orbital tooth triangular, directed obliquely outwards, representing point of greatest width of carapace; lateral margins straight, slightly converging posteriorly, without trace of tooth or indentation behind external orbital tooth. Cornea ( Fig. 3A View Fig ) reaching tip of external orbital tooth. Basal articles of antennae and antennules adjacent, not separated by septum; basal antennular article swollen; antennal flagellum relatively long, entering orbit. Third maxilliped with ischium bearing shallow median sulcus; merus with distinct submedian ridge; exopod slender, tip reaching half-length of outer margin of merus, flagellum long.
Male chelipeds ( Figs. 3C, D View Fig , 4B–D View Fig ) relatively large, robust. Merus with carinate outer margin, without subdistal spine; inner margin with small granules ending in large subdistal protuberance; outer surface with dorsal striation, ventrally tuberculate. Carpus with inner angle not produced. Palm with 2 transverse pectinate crests on upper surface; distal crest composed of 15 (right chela) and 14 (left chela) high corneous teeth; distal crest well developed, shorter than proximal crest, with 10 (right chela) and 8 (left chela) corneous teeth; crests followed by several tubercles; rows of small tubercles below second crest; outer and inner surfaces of palm with numerous granules. Fingers each with chitinous tip, with distinct proximal hiatus; cutting edges each with row of rounded teeth; fixed finger smooth on outer surface; dactylus with 12 asymmetrical tubercles (both chelae) on upper surface, tubercles short, gradually sloping distally; proximal 4 tubercles large, distal 8 tubercles smaller, last tubercle almost indiscernible.
Ambulatory legs ( Fig. 3A View Fig ) slender, laterally flattened; P3 and P4 subequal, longer than others, about 1.5 times carapace width. Merus of P3 2.1 times as long as broad; upper margin with acute subdistal spine. Meri of P2–P5 each with transverse striae on upper surface. Carpi of P2–P5 each with 2 accessory carinae on outer surface. Propodus of P3 2.4 times as long as broad, with striae on inferior proximal portion of outer surface, dorsal and ventral margins with short stiff setae. Dactylus of P3 0.8 times length of propodus, slightly curved distally, terminating in acute calcareous tip; dorsal and ventral margins with short stiff setae.
Thoracic sternites 1–3 completely fused. Male pleon ( Fig. 11A View Fig ) relatively broad, all somites free. Telson semicircular, evenly rounded, as long as preceding somite. Somite 6 almost twice as long as wide, lateral margins slightly convex. Somites 3–5 more trapezoidal, lateral margins of somites 4 and 5 straight, lateral margins of somite 3 strongly convex. Somites 1 and 2 very narrow longitudinally. G1 ( Fig. 4E View Fig ) straight, relatively stout; apical process short, corneous part short, ending in truncate tip; setae long, simple, originating at base of apical process. G2 shorter than quarter length of G1.
Female characters: Chelipeds relatively small, pectinate crest on palms indistinct, dactylar tubercles low; pleon wide, rounded, telson semicircular, base half embedded in distal margin of somite 6; vulva ( Figs. 3G View Fig , 4F View Fig ) near anterior edge of sternite 5, with central operculum, oval shaped.
Variation: The number of teeth on the two transverse pectinate crests of the palms are variable with 14–19 (distal part) and 8 or 9 (proximal part). Some male specimens with some teeth on the two transverse pectinate crests are weak, probably due to damage or abrasion, but they can be observed by the residual trace. The number of tubercles on the upper surface of chelipedal dactyli is 12–15. The vulvae are near or close to anterior edge of sternite 5, and the central operculum is relatively raised in larger specimens ( CW > 11.0 mm).
Colour in life: Carapace dark brown with a transverse golden-yellow band on frontal region, cheliped and ambulatory legs light brown, palm yellow to orange ( Figs. 1A, B View Fig , 2A–D View Fig ). The carapace of some female specimens is yellow, which makes the transverse golden-yellow band on the frontal region less obvious.
Distribution: So far known from Taiwan (estuaries of Baoli R. and Gangkou R.) and the Philippines (Kawasan, Cebu).
Etymology: The name “ aurifrons ” refers to the frontal band which is golden yellow in life. The name is used as a noun in apposition.
Ecological notes: In the Gangkou R. estuary, southern Taiwan, P. aurifrons is partly sympatric with P. kuekenthali (De Man, 1902) , Sesarmops intermedius (De Haan, 1835) and Neosarmatium indicum (A. Milne-Edwards, 1868) . Ovigerous females were found from June to September, suggesting that summer is the main reproductive season. We found that individuals will climb to the adjacent vegetation during high tide ( Fig. 2C, D View Fig ) and stay on the mudflat or in burrows during low tide. This behaviour is similar to the niche shifting behaviour reported in the Indian P. plicatum (Latreille, 1806) to escape from potential aquatic predators ( Shanij et al. 2016). Ng and Schubart (2017: 663) also noted that Pseudosesarma crassimanum (De Man, 1887) also sometimes climbs low shrubs, especially at night, although it usually forages on the ground.
Remarks: Li and Chiu (2013: 81) depicted several ovigerous females of “ Parasesarma aff. ungulatum ” from Hengchun Peninsula, Pingtung, southern Taiwan, with a yellow band on its front. While their material superficially resembles P. ungulatum (H. Milne Edwards, 1853) from Sulawesi and Papua, Indonesia and eastern Thailand ( Rahayu and Ng 2010: fig. 8), Li and Chiu (2013) noted that the general carapace and ambulatory leg features appeared somewhat different. Direct comparisons of both now show that they are different species.
The most important characters to distinguish P. aurifrons and P. ungulatum are the mature adult size (max. CW 15.4 mm versus 21.4 mm), the ratio of CW/ CL of carapace (1.2 versus 1.3), and the length of ambulatory legs (relative more elongated versus relative shorter) (cf. Rahayu and Ng 2010). In addition, the length of the G1 tip is also proportionately shorter in P. aurifrons ( Figs. 3E, F View Fig , 4E View Fig ) (longer in P. ungulatum ; cf. Rahayu & Ng 2010: fig. 10A–D).
In the BI tree ( Fig. 13 View Fig ; see below), P. aurifrons is close to P. liho Koller, Liu & Schubart, 2010 , P. paucitorum Rahayu & Ng, 2009 , and P. obliquifrons ( Rathbun, 1924) , despite its different appearance. Parasesarma aurifrons can easily be separated from P. liho by its life coloration, especially the golden frontal band ( Figs. 1A View Fig , 2A, B View Fig ) (versus absent in P. liho ); relatively broader carapace (width to length ratio 1.2, Figs. 1A View Fig , 4A View Fig ) (versus 1.1 in P. liho ), the dorsal surface is glabrous without distinct setae ( Figs. 1A View Fig , 4A View Fig ) (versus surface rougher with distinct setae in P. liho ), and the ambulatory propodi are proportionately shorter ( Figs. 1A–B View Fig , 2A View Fig ) (versus distinctly longer in P. liho ) (cf. Koller et al. 2010; Shih et al. 2019). The latter species, however, has a different colour in life (it lacks the distinct golden frontal band) and the ambulatory propodus and merus are proportionately more elongate and slender (cf. Rahayu and Ng 2009: figs. 1A, 3A).
Parasesarma obliquifrons View in CoL is a poorly known species described from Samoa, but it has never been figured and its affinities are uncertain. Rathbun (1924: 127) recorded one holotype male 12.8 × 11.3 mm (USNM 45913), but made no mention of any other material. The USNM contains one bottle labelled USNM 45913, but it contains a total of five male and nine female specimens. The largest male matches the measurements and description in Rathbun (1924: 127– 128) and is clearly the holotype. The other specimens are not types, as they were not mentioned at the time of description. The holotype, including the important G1 structure, is figured here for the first time ( Figs. 5 View Fig , 6 View Fig ). Parasesarma aurifrons View in CoL can be distinguished from P. obliquefrons in having the frontal margin straighter and the median cleft hallow to almost not visible in dorsal view ( Figs. 3A View Fig , 4A View Fig ) (versus frontal margin distinctly sinuous with the median cleft pronounced in P. obliquefrons ; Fig. 5A View Fig ); the dorsal surface of the cheliped dactylus has 12 smaller tubercles ( Figs. 3C, D View Fig , 4C View Fig ) (versus dactylus with only 5 or 6 low, broad, simple tubercles in P. obliquefrons ; Fig. 5E, F View Fig ); the male pleon is relatively wider ( Figs. 1B View Fig , 11A View Fig ) (versus relatively narrower in P. obliquefrons ; Fig. 5C View Fig ); and most significantly, the G1 is proportionately more slender and the corneous distal part is directed more obliquely laterally ( Figs. 3E, F View Fig , 4E View Fig ) (versus G1 proportionately stouter with the corneous distal part directed more vertically in P. obliquefrons ; Fig. 6A–D View Fig ).
Parasesarma sanguimanus View in CoL n. sp. ( Figs. 1C, D View Fig , 2E View Fig , 7A, B, E, F, I, J, K View Fig , 8A–D View Fig , 11B View Fig ) urn:lsid:zoobank.org:act:552ACCAF-91F2-4519-9E01-0DBA589F2F4D
Material examined: Holotype: 1 ò (15.2 × 13.0 mm) (NCHUZOOL 15623), Gangkou R. estuary (21°59'16.1"N 120°50'29.7"E), Hengchun, Pingtung, Taiwan, coll. J.-J. Li, 8 Jul. 2017 GoogleMaps . Paratypes: Taiwan: Gangkou R. estuary, Hengchun, Pingtung: 1 ò (12.3 × 10.0 mm) (NCHUZOOL 15632), coll. J.-J. Li, 10 Apr. 2014; 3 òò (14.1–14.6 × 12.0– 12.1 mm) (NCHUZOOL 15625), coll. J.-J. Li, 10 Apr. 2015; 3 òò (12.1–14.6 × 9.9–11.7 mm) (NCHUZOOL 15629), coll. J.-J. Li, 11 Apr. 2015; 1 ò (15.5 × 13.0 mm) (NCHUZOOL 15630), coll. J.-J. Li, 18 May 2015; 1 ò (17.5 × 14.2 mm) (NCHUZOOL 15525), coll. J.-J. Li, 15 Jun. 2015; 1 ò (19.0 × 15.6 mm) (NCHUZOOL 15628), coll. J.-J. Li, 7 Jul. 2015; 1 ò (18.5 × 15.9 mm) (NCHUZOOL 15624), 1 ò (17.6 × 15.1 mm) (NCHUZOOL 15626), coll. J.-J. Li, 8 May 2016; 1 ò (18.4 × 15.0 mm) ( ZRC 2019.1080), coll. J.-J. Li, 14 May 2016.1 ñ (12.0 × 9.8 mm) (NCHUZOOL 15631), coll. J.-J. Li, 21 Mar. 2016; 3 òò (5.9–7.4 × 2.9–4.7 mm), 1 female (4.3 × 1.9 mm) ( ZRC 2019.0821), coll. J.-J. Li, 18 Jun. 2016; 1 ò (13.8 × 11.6 mm) (NCHUZOOL 15627), coll. J.-J. Li, 17 Jul. 2017; 1 ò (16.7 × 13.9 mm) ( ZRC 2019.0820), coll. J.- J. Li, 7 Jul. 2018; 1 ò (13.2 × 10.9 mm) (NCHUZOOL 15714), coll. J.-J. Li, 28 Aug. 2018. Baoli R. estuary (22°03'30.5"N 120°42'29.8"E), Hengchun, Pingtung: 1 ò (19.0 × 15.3 mm) (NCHUZOOL 15633), coll. J.-J. Li, 24 Jul. 2014.
Comparative material: Parasesarma bidens (De Haan, 1835) : 2 òò (18.1 × 14.9 mm, 29.4 × 24.9 mm) (NCHUZOOL 15634), Okinawa, Japan, coll. J.-J. Li, 18 Jul. 2016; 5 òò (28.9–31.6 × 23.0– 25.6 mm) (NCHUZOOL 15635), Kyushu, Japan, coll. T. Naruse et al., 3 Oct. 2017; 5 òò (15.7–25.5 × 12.6–21.7 mm) (NCHUZOOL 15636), Sicao, Tainan, Taiwan, coll. J.-J. Li, 4 Oct. 2015; 2 òò (16.5 × 13.6 mm, 18.5 × 15.8 mm) (NCHUZOOL 15637), Baoli R. estuary, Taiwan, coll. J.-J. Li, 19 Mar. 2016; 2 òò (16.7 × 13.4, 18.8 × 15.3 mm) ( ZRC 2002.0561), Xiamen, Fujian, China, coll. P. K. L. Ng, 22 Sep. 2002; 10 òò (13.6–17.3 × 14.2– 11.6 mm), 1 ñ (14.7 × 11.9 mm) (NCHUZOOL 15638), Kinmen, Taiwan, coll. J.-J. Li, 2 Jul. 2017. Parasesarma cricotus ( Rahayu & Davie, 2002) : 2 òò (18.7 × 4.9 mm, 19.2 × 15.0 mm), 2 ññ (12.8 × 10.3, 16.9 × 3.5 mm) ( MZB), Tipocka River, Papua, Indonesia, coll. D. L. Rahayu, 14 Mar. 2017. Parasesarma foresti (Rahayu & Davie, 2001) : 1 ò (23.3 × 19.4 mm) ( ZRC 2002.0608), Tipocka, Portsite, Papua, Indonesia, coll. Gesang, 13 Aug. 2002. Parasesarma indiarum (Tweedie, 1940) : 1 ò (24.1 × 20.7 mm) ( ZRC 2013.1613), Pasir Ris Park mangroves, Singapore, coll. B. Y. Lee, 28 Oct. 2011; 1 ñ (24.9 × 19.8 mm) ( ZRC 2000.1982), Mandai mangroves, Singapore, coll. C. D. Schubart and N. Sivasothi, 25 Jul. 2000. Parasesarma semperi ( Bürger, 1893) : 2 òò (20.8 × 17.8 mm, 23.5 × 19.5 mm) ( ZRC 2015.0464), Sungcolan inlet, fringe mangroves, Panglao, Bohol, Philippines, coll. Panglao 2004 Expedition, 4 Jul. 2004. Parasesarma nr. lividum (A. Milne-Edwards, 1869) : 1 ò (23.5 × 19.6 mm) (RUMF-ZC-3779), Miyara R., Ishigaki Island, Ryukyu Islands, Japan, coll. T. Maenosono, 26 Mar. 2016.
Diagnosis: Carapace ( Figs. 1C View Fig , 7A View Fig ) squarish in dorsal view, 1.2 times broader than long; front with margin straight in dorsal view; external orbital tooth triangular, directed obliquely outwards, representing point of greatest width of carapace; lateral margins straight, slightly converging posteriorly, without trace of tooth or indentation behind external orbital tooth. Male chela ( Figs. 7E, F View Fig , 8A, B View Fig ) with 2 transverse pectinate crests on upper surface; distal crest composed of 13–19 high corneous teeth; second crest well developed, shorter than proximal crest, with 9–16 corneous teeth; dactylus with 10–12 asymmetrical tubercles on upper surface, proximal tubercle smallest but distinct. Ambulatory legs ( Figs. 1C View Fig , 7A View Fig ) slender; P3 and P4 about 1.6 times carapace width; merus of P3 2.3 times as long as broad; upper margin with acute subdistal spine; propodus of P3 3.1 times as long as broad; dactylus of P3 1.3 times length of propodus. Male pleon ( Figs. 1D View Fig , 11B View Fig ) relatively broad, telson semicircular, somite 6 almost twice as long as wide, lateral margins slightly convex. G1 ( Figs. 7I, J View Fig , 8C View Fig ) straight, relatively stout; apical process very short, corneous part short, ending in truncate tip; setae long, simple, originating at base of apical process. Vulva ( Figs. 7K View Fig , 8D View Fig ) near anterior edge of sternite 5, with central operculum, oval shaped, protruded.
Description of holotype male: Carapace ( Fig. 7A View Fig ) almost squarish in dorsal view, 1.2 times broader than long; regions well defined, separated by shallow grooves; upper surface laterally with oblique striae, otherwise smooth; postfrontal region well delimited, separated into 4 lobes by shallow but distinct grooves; median lobes almost as wide as lateral lobes; front ( Fig. 7B View Fig ) deflexed downwards, margin straight in dorsal view; supraorbital margin gently convex; external orbital tooth triangular, directed obliquely outwards, representing point of greatest width of carapace; lateral margins straight, slightly converging posteriorly, without trace of tooth or indentation behind external orbital tooth. Cornea exceeding tip of external orbital tooth ( Fig. 7A View Fig ). Basal articles of antennae and antennules adjacent, not separated by septum; basal antennular article swollen; antennal flagellum relatively long, entering orbit. Third maxilliped with ischium bearing shallow median sulcus; merus with distinct submedian ridge; exopod slender, tip reaching half-length of outer margin of merus, flagellum long.
Male chelipeds ( Figs. 7E, F View Fig , 8A, B View Fig ) relatively large, robust. Merus with carinate outer margin, without subdistal spine; inner margin with small granules ending in large subdistal protuberance; outer surface with dorsal striation, ventrally granulate. Carpus with inner angle not produced. Palm with 2 transverse pectinate crests on upper surface; distal crest composed of 17 (right chela) and 14 (left chela) high corneous teeth; second crest well developed, shorter than proximal crest, with 13 (right chela) and 10 (left chela) corneous teeth; crests followed by several tubercles; rows of small tubercles below second crest; outer and inner surfaces of palm with numerous granules. Fingers each with chitinous tip, with distinct proximal hiatus; cutting edges each with row of rounded teeth; fixed finger smooth on outer surface; dactylus with 12 asymmetrical tubercles (both chelae) on upper surface, proximal tubercle smallest but distinct.
Ambulatory legs ( Fig. 7A View Fig ) slender, laterally flattened; P3 and P4 subequal, longer than others, about 1.6 times carapace width. Merus of P3 2.3 times as long as broad; upper margin with acute subdistal spine. Meri of P2–P5 with transverse striae on upper surface. Carpus of P2–P5 with 2 accessory carinae on outer surface. Propodus of P3 3.1 times as long as broad, with striae on inferior proximal portion of outer surface, dorsal and ventral margins with short stiff setae. Dactylus of P3 1.3 times length of propodus, slightly curved distally, terminating in acute calcareous tip; dorsal and ventral margins with short stiff setae.
Thoracic sternites 1–3 completely fused. Male pleon relatively broad, all somites free. Telson semicircular, evenly rounded, as long as preceding somite. Somite 6 almost twice as long as wide, lateral margins slightly convex. Somites 3–5 more trapezoidal, lateral margins of somites 4 and 5 straight, lateral margins of somite 3 strongly convex. Somites 1 and 2 very narrow longitudinally. G1 straight, relatively stout ( Fig. 8C View Fig ); apical process very short, corneous part short, ending in truncated tip; setae long, simple, originating at base of apical process. G2 shorter than quarter length of G1.
Female characters: Chelipeds relatively small, pectinate crest on palms indistinct, dactylar tubercles low; pleon wide, rounded, telson semicircular, base half embedded in somite 6; vulva ( Figs. 7K View Fig , 8D View Fig ) near anterior edge of sternite 5, with central operculum, oval shaped, protruded.
Variation: The number of teeth on the two transverse pectinate crests of the palms are variable with 13–19 (distal part) and 9–16 (proximal part). Some male specimens with some teeth on the two transverse pectinate crests are weak, probably due to damage or abrasion, but they can be observed by the residual trace. The number of tubercles on the upper surface of chelipedal dactyli varies 10– 12.
Colour in life: Carapace and cheliped dark gray (palm exception). Cheliped palm outer surface deep red, inner surface yellowish orange ( Figs. 1C, D View Fig , 2E View Fig ).
Distribution: So far known from the estuaries of Baoli R. and Gangkou R. in Hengchun, Pingtung, southern Taiwan.
Etymology: The name is derived from the Latin “ sanguineus ” for blood-red, and “ manus ” (for hand); alluding to the deep-red palm of the species in life. The name is used as a noun.
Ecological notes: The habitat and behaviour of P. sanguimanus are generally similar to those of P. aurifrons n. sp. except that most specimens were collected closer to the water’s edge.
Remarks: Among the Taiwanese Parasesarma species ( Ng et al. 2001 2017), the only other species with two anterolateral teeth on the carapace is P. bidens (De Haan, 1835) . Parasesarma sanguimanus n. sp. is found sympatrically with P. bidens and their morphology is superficially similar, but can be distinguished by the deep-red outer surface of the palm in life ( Fig. 2E View Fig ) (versus yellow to orange in P. bidens ) and the ringed grooves on the upper surface of the dactylar tubercles ( Figs. 7F View Fig , 8B View Fig ) (versus without grooves in P. bidens ) (cf. Li and Chiu 2013: 54).
Among the Indo-West Pacific Parasesarma , P. foresti ( Rahayu & Davie, 2002) , P. indiarum (Tweedie, 1940) , P. holthuisi ( Davie, 2010) , P. guttatum (A. Milne-Edwards, 1869) , P. brevicristatum (Campbell, 1967) and P. dussumieri (A. Milne-Edwards, 1853) have a similar number of male dactylar tubercles (11–13) to P. sanguimanus , but none of them have ringed grooves on the tubercles (cf. Davie 2010; Rahayu and Davie 2002). Species which have similar grooves on the dactylar tubercles however, have distinctly fewer tubercles: P. semperi ( Bürger, 1893) has 7 or 8 dactylar tubercles (cf. Bürger 1893; Davie 2010; Shahdadi et al. 2018); and male P. maipoense ( Soh, 1978) has 5–8 dactylar tubercles (cf. Soh 1978; Ng et al. 2010).
According to the BI tree ( Fig. 13 View Fig ; see below), P. sanguimanus is sister to P. cricotus ( Rahayu & Davie, 2002) . Their morphologies are superficially similar, both possessing 11 or 12 dactylar ringed tubercles in males and with a similar colour in life ( Rahayu and Davie 2002). Parasesarma sanguimanus , however, can be distinguished by its more rounded dactylar tubercles (especially the second to fifth tubercles) ( Fig. 8B View Fig ) (versus relatively ovate in P. cricotus ; Fig. 8E View Fig ); a proportionately wider G1 tip ( Figs. 7I, J View Fig , 8C View Fig ) (versus more narrow in P. cricotus ; Fig. 8F View Fig ); and the relatively smaller and lower female operculum of the vulva ( Figs. 7K View Fig , 8D View Fig ) (larger in P. cricotus ; Fig. 8G View Fig ). Both species can be separated in the field by the coloration of carapace; P. cricotus has clear light spots on the gastric region and frontal region ( Rahayu and Setyadi 2009: 53; also see Fig. 7C View Fig ), but these are absent in P. sanguimanus ( Fig. 1C View Fig ).
Parasesarma gemmatum n. sp. ( Figs. 1E–G View Fig , 2F View Fig , 9 View Fig , 10 View Fig , 11C View Fig ) urn:lsid:zoobank.org:act:A8F0E575-86C0-41AB-A7BB-4B9F0002926A
Material examined: Holotype:ò (15.7 × 13.1 mm) (NCHUZOOL 15639), Dingtanzih, Hengchun, Pingtung, Taiwan, coll. J.-J. Li, 13 Jun. 2019 . Paratypes: Taiwan: Hengchun, Pingtung: 1 ò (14.8 × 12.4 mm) (NCHUZOOL 15532), Dingtanzih, coll. J.-J. Li, 21 Aug. 2018; 1 ò (12.8 × 10.5 mm), 1 ovig. ñ (11.7 × 9.8 mm) ( ZRC 2019.1076), Tanzih Fishing Port, coll. J.-J. Li, 3 Jun. 2019; 1 ovig. ñ (14.2 × 11.7 mm) (NCHUZOOL 15640), Tanzih Fishing Port, coll. J.-J. Li, 24 Sep. 2018; 1 ñ (14.4 × 10.4 mm) (NCHUZOOL 15531), Siatanzih, coll. J.-H. Lee, 31 Aug. 2012; 2 ññ (8.7 × 7.1 mm, 11.6 × 9.1 mm), 1 ovig. ñ (12.8 × 10.4 mm) (NCHUZOOL 15641), Tanzih Fishing Port, coll. J.-J. Li, 27 May 2019; 1 ò (15.0 × 12.4 mm) (NCHUZOOL 15707), Tanzih Fishing Port, J.-J. Li, 28 Jun. 2019; 1 ò (14.7 × 11.9 mm) (NCHUZOOL 15708), east coast to Tanzih Fishing Port, J.-J. Li., 4 Jul. 2019.
Comparative material: Parasesarma anambas Yeo, Rahayu & Ng, 2004 : paratype: 1 ò (8.1 × 7.1 mm), 1 ñ (4.2 × 3.4 mm) ( ZRC 2003.0726), Teluk Baruk, Anambas, eastern Pulau Siantan, 15 Mar. 2002; 1 ò (10.1 × 8.0 mm) (NCHUZOOL 15514), Sanya, Hainan, China, coll. H.- T. Shih, 28 Jun. 2004.
Diagnosis: Carapace ( Figs. 1E, F View Fig , 9A, C View Fig , 10A View Fig ) almost squarish in dorsal view, 1.2 times broader than long; front with margin gently concave in dorsal view; external orbital tooth sharp triangular, directed obliquely outwards, representing point of greatest width of carapace; lateral margins straight, slightly converging posteriorly, without trace of tooth or indentation behind external orbital tooth. Male chela ( Figs. 1E, G View Fig , 9A, E, F View Fig , 10B, C View Fig ) with 3–5 transverse granules row on upper surface, not pecinated, not corneous; outer and inner surfaces of palm with numerous granules; dactylus upper surface with 14–22 asymmetrical tubercles, starting at proximal or subproximal part of finger. Ambulatory legs ( Figs. 1E–G View Fig , 9A–C View Fig ) slender, P3 and P4 about 1.6 times carapace width; merus of P3 2.8 times as long as broad; upper margin with acute subdistal spine; meri of P2–P5 each with transverse striae on upper surface; propodus of P3 3.3 times as long as broad; dactylus of P3 1.2 times length of propodus. Male pleon ( Figs. 1G View Fig , 10G, H View Fig , 11C View Fig ) relatively broad; telson semicircular, base central edge embedded in distal margin of somite 6; somite 6 0.6 to 0.7 times as long as wide, lateral margins slightly convex. G1 ( Figs. 9G, H View Fig , 10D, E View Fig ) straight, relatively stout; apical process short, corneous part wide, ending in truncated tip; setae long, simple, originating at base of apical process. Vulva ( Figs. 9I View Fig , 10F View Fig ) near anterior edge of sternite 5, with central operculum, cone-shaped.
Description of holotype male: Carapace ( Fig. 1E View Fig ) almost squarish in dorsal view, 1.2 times broader than long; regions well defined, separated by shallow grooves; postfrontal region well delimited, separated into 4 lobes by shallow but distinct grooves; median lobes slightly broader than lateral lobes; front deflexed downwards, margin gently concave in dorsal view; supraorbital margin slightly convex; external orbital tooth sharp triangular, directed obliquely outwards, representing point of greatest width; lateral margins straight, slightly converging posteriorly, without trace of tooth or indentation behind external orbital tooth. Cornea ( Fig. 1E View Fig ) exceeding tip of external orbital tooth. Basal articles of antennae and antennules adjacent, not separated by septum; basal antennular article swollen; antennal flagellum relatively long, entering orbit. Third maxilliped with ischium bearing shallow median sulcus; merus with distinct submedian ridge; exopod slender, tip reaching half-length of outer margin of merus, flagellum long.
Male chelipeds ( Figs. 1E View Fig , 10B View Fig ) relatively large, robust. Merus with carinate outer margin, without subdistal spine; inner margin with small granules ending in large subdistal protuberance; outer surface with dorsal striation, ventrally tuberculate. Carpus with inner angle not produced. Palm with 3 transverse nonpecinated granule rows on upper surface, not corneous; outer and inner surfaces of palm with numerous granules. Fingers each with chitinous tip, with distinct proximal hiatus; cutting edges each with row of rounded teeth; fixed finger smooth on outer surface; dactylus upper surface with 22 asymmetrical tubercles, proximal 9 tubercles oval shaped, each with dorsal keel; distal 5 tubercles rounded, smooth.
Ambulatory legs ( Figs. 1E View Fig ) slender, laterally flattened; P3 and P4 subequal, slightly longer than others, about 1.6 times carapace width. Merus of P3 2.8 times as long as broad; upper margin with acute subdistal spine. Meri of P2–P5 each with transverse striae on upper surface. Carpi of P2–P5 each with 2 accessory carinae on outer surface. Propodus of P3 3.3 times as long as broad, with striae on inferior proximal portion of outer surface, dorsal and ventral margins with short stiff setae. Dactylus of P3 1.2 times length of propodus, slightly curved distally, terminating in acute calcareous tip; dorsal and ventral margins with short stiff setae.
Thoracic sternites 1–3 ( Fig. 1G View Fig ) completely fused. Male pleon ( Figs. 10G View Fig , 11C View Fig ) relatively broad, all somites free. Telson semicircular, evenly rounded, as long as preceding somite, base central edge embedded in distal margin of somite 6. Somite 6 almost 0.6 times as long as wide, lateral margins slightly convex. Somites 3–5 more trapezoidal, lateral margins of somites 4 and 5 straight, lateral margins of somite 3 strongly convex. Somites 1 and 2 very narrow longitudinally. G1 straight, relatively stout; apical process short, corneous part wide, ending in truncated tip; setae long, simple, originating at base of apical process. G2 shorter than quarter length of G1.
Female characters: Chelipeds ( Fig. 9C, D View Fig ) relatively small, granules on palms indistinct, dactylar tubercles low; pleon ( Fig. 9D View Fig ) wide, rounded, telson semicircular, base half embedded in distal margin of somite 6; vulva ( Figs. 9I View Fig , 10F View Fig ) near anterior edge of sternite 5, with central operculum, cone-shaped.
Variation: Based on the male specimens examined, the length of the row of granules on dactylar upper surface is variable, being longer and reaching to the palm ( Fig. 10B View Fig ) in larger specimens, but is relatively shorter and not reaching the palm ( Fig. 10C View Fig ) in smaller crabs. The length of male somite 6 is relatively shorter (0.6 times as long as wide; Fig. 10G View Fig ) in largest specimens (the holotype), but is proportionately longer (0.7 times as long as wide; Fig. 10H View Fig ) in smaller ones.
Colour in life: Carapace and ambulatory legs dark greenish-brown, with yellowish-green patches; cheliped yellow, fingers with orange tips ( Figs. 1E–G View Fig , 2F View Fig ).
Distribution: Only known from southern Taiwan.
Etymology: The species name is derived from the Latin “ gemmatus ” which means covered in small gems, alluding to the light-coloured jewel-like spots on the carapace.
Ecological notes: Parasesarma gemmatum was only found in eroded limestone with many crevices in supratidal zone, located on the outer edge of coastal forest. The species is sometimes sympatric with P. lenzii (De Man, 1895) (see DISCUSSION) and Chiromantes leptomerus Davie & Ng, 2013 from Taiwan.
Remarks: Parasesarma gemmatum is superficially most similar to P. lenzii (De Man, 1895) (see Comparative material) in having a similar coloration, especially the yellowish-green patches, but the margins of the patches are indistinct in the former ( Fig. 1F View Fig ) and distinct in the latter ( Shahdadi et al. 2019b: fig. 3). In the external morphology, P. gemmatum can most easily be separated from P. lenzii by the dorsal surface of the male chela possessing rows of non-pectinated granules that do not have corneous tips ( Fig. 10C View Fig ) (versus with pectinated crests of corneous granules in P. lenzii and all other Parasesarma species; Shahdadi et al. 2019b: fig. 1C); the base of the male telson is partially embedded in the distal margin of somite 6 ( Fig. 10F–G View Fig ) (versus base not embedded in somite 6 in P. lenzii ; Shahdadi et al. 2019b: fig. 1E); the male G1 is relatively stouter ( Figs. 9G, H View Fig , 10D, E View Fig ) (versus G1 more slender in P. lenzii ; Shahdadi et al. 2019b: fig. 1F–G); and the female vulva has a cone-shaped operculum protruding upwards ( Figs. 9I View Fig , 10F View Fig ) (versus with triangular operculum which protrudes downwards in P. lenzii ; Shahdadi et al. 2019b: fig. 2D). The latter species is also shown to be present in Taiwan, as a new record (see later).
The absence of a pectinated crest of granules on the dorsal surface of the male chela ( Fig. 10C View Fig ) is a unique character of P. gemmatum ; all other congeners have this feature distinct, even if not all the granules are pectinated. There is precedence; in the West African Guinearma Shahdadi & Schubart, 2017 , two of the species have distinct pectinated crests, with the crest of one taxon, G. kamermani (De Man, 1883) composed only of simple granules ( Shahdadi et al. 2019a).
According to the BI tree ( Fig. 13 View Fig ), P. anambas Yeo, Rahayu & Ng, 2004 , from Anambas, Indonesia and Hainan, China, is sister to P. gemmatum n. sp. Both species are similar in carapace shape and G1 morphology, but P. gemmatum without transverse pectinate crests on upper surface of palm ( Fig. 10C View Fig ) (versus three transverse pectinate in P. anambas ; Yeo et al. 2004: fig. 2b); the upper surface of the cheliped dactylus lined with closely spaced 22 tubercles ( Fig. 10B View Fig ) (versus more distantly spaced 17 tubercles in P. anambas ; Yeo et al. 2004: fig. 2b); and the G1 is stout with the corneous distal process short and wide ( Figs. 9G, H View Fig , 10D, E View Fig ) (versus G1 slender, corneous distal process strongly produced and long in P. anambas ; Yeo et al. 2004: fig. 2f).
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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Parasesarma aurifrons
| Li, Jheng-Jhang, Shih, Hsi-Te & Ng, Peter K. L. 2019 |
Parasesarma aff. ungulatum
| Li JJ & Chiu YW 2013: 81 |