Caridina peninsularis Kemp, 1918

Richard, Jasmine & Clark, Paul F., 2014, Caridina simoni Bouvier, 1904 (Crustacea: Decapoda: Caridea: Atyoidea: Atyidae) and the synonymy by Johnson, 1963, Zootaxa 3841 (3), pp. 301-338 : 315-321

Caridina peninsularis Kemp, 1918

( Figs. 6–10 )

Caridina brachydactyla subsp. peninsularis Kemp, 1918: 279 , fig. 10a–g; Johnson, 1961b: 45.

Caridina brachydactyla var. peninsularis Bouvier, 1925: 155 , figs. 321–322.

Caridina brachydactyla peninsularis Dutt & Ravindranath, 1975: 269 –270 .

Caridina simoni peninsularis de Silva 1983: 209 .

Caridina peninsularis Wowor et al., 2004: 343 (key), fig. 6J–L; Cai & Shokita, 2006: 248; Cai et al., 2007: 280 , figs. 2–3.

Caridina mccullochi J. Roux, 1926b: 249 ; Reik, 1953: 118.

Caridina meridionalis J. Roux, 1926a: 207 (partim).

Material examined. Types: Cotype. Malaysia. C. brachydactyla subsp. peninsularis , Botanical garden, Penang Island, coll. N. Anandale, Feb. 1916, Indian Museum, NHM reg. 1919.11.1.12–21, 1♂, 1♀ ovig., 10♀.

Non types: Singapore. Tanglin (incorrectly spelt Tangtum in NHM register and on label), coll. Bedford & Lanchester, det. D.S. Johnson, 1958, NHM reg. 1958.8.7.14–17, 3♂, 3♀ ovig. and 1 specimen which is not a Caridina .

Other material: Caridina mccullochi . Types: Types. Australia. Pallal, Horton River , near Bingara, N.S.W., exch. with Sydney, 1923, NMB reg. 737a, 1♂, 3♀ ovig.; Syntypes. Pallal, Hoton River, near Bingra, N.S.W., coll. A.R. Mc Culloch, Dec. 1909, AM reg. P.7920, 1♂, (1st pleopods missing), 3♀ ovig.; North Yanco, Narrandera, N.S.W., 34.75ºS 146.92ºE, coll. 18 Jan. 1910, det. J. Roux, AM reg. P.7921, 3♀ (rostrum damaged in one specimen). All now C. peninsularis Kemp, 1918 .

Caridina nilotica var. meridionalis . Cotype: New Caledonia. Coindé, coll. J. Roux & F. Sarasin, 12 Jan. 1912, NMB 4.VIII. g 1♂. Now C. peninsularis Kemp, 1918 .

Description. Adult size 25–32 mm. Carapace length 3.5–4.5 mm.

Rostrum ( Figs. 6 a, b; 8a ; 9a, b): Rostrum equal to, or slightly shorter longer than antennal scale. 0.85–1.0×long as carapace. Tip pointed. 20–37 teeth on the dorsal margin either uninterrupted up to the tip or with a short distal unarmed margin interrupted by teeth, distal 3–7 teeth spaced. 2–4 post orbital teeth present. 7–22 teeth on the ventral margin either up to the tip or with a short distal unarmed margin. Tip pointed. Formula (2–4) 20–37/7–22.

Antennular peduncle: ( Figs. 6 a, b; 8a ; 9a, b) 0.7–0.8×carapace. Stylocerite 0.6–0.8×length of basal segment. Anterolateral teeth of basal segment 0.15–0.30×second segment. 15–20 segments bearing aesthetascs.

First pereiopod ( Figs. 7 a; 10a): Dactylus 1.2–1.5×palm of propodus. Chela 2.1–2.5×long as broad. Carpus 2.6–3.1×long as broad with anterior excavation.

Second pereiopod ( Figs. 7 b; 10b): Dactylus 1.4–1.7×long as palm of propodus. Chela 2.7–3.2×long as broad. Carpus 5.2–6.5×long as broad.

Third pereiopod ( Figs. 7 c, d; 10c, d): Dactylus 2.5–4.0×long as broad. 6–8 spines on dactylus (including terminal spine). Propodus 4.5–6.1×long as dactylus and 12–15×long as broad with 12–16 spines arranged along inner margin. Carpus 0.6–0.7×long as propodus with 1 large spine and 2–3 minute spines on inner margin. Merus 1.6–1.9×carpus length. Merus with 3 large spines on posterior margin.

Fifth pereiopod ( Figs. 7 e, f; 10e, f): Dactylus 4.2–5.0×long as broad with 39–50 spines arranged in comb-like fashion on inner margin. Propodus 12–15×long as broad and 3.5–5.0×long as dactylus and with 12–18 spines along posterior margin. Carpus 0.45–0.6×propodus length and with 1 large spine and 3–4 minute spines along inner margin. Merus 1.5–1.9×carpus length, with 2 large spines at posterior margin.

Setobranchs: 2 or 3 setae on all pereiopods.

First male pleopod ( Figs. 7 g; 10g, h): A distinct appendix interna present. Several long setae present along the entire margin.

First female pleopod: Endopod 0.5–0.65×exopod length.

Eggs ( Figs. 7 h; 10i): ca. 350 eggs of 0.49–0.58× 0.23–0.35 mm size.

Second male pleopod ( Figs. 7 i; 10j, k): Appendix masculina 1.3–1.6×appendix interna and 0.25–0.3×endopod.

6th abdominal somite: 0.60–0.75×long as carapace.

Telson ( Figs. 7 j, k; 10l, m): Broad, 1–1.1×long as 6th abdominal somite. Dorsal spines 4–6 pairs including subterminal spine. Posterior margin broad and moderately triangular with or without median process, bearing 1 pair of lateral spines and 2–3 pairs of long spines of equal length or the median pair fractionally longer than the outer spines.

Uropod ( Figs. 7 l; 10n): 10–16 diaeresis spinules.

Preanal carina ( Figs. 7 m; 10o): Armed or unarmed.

Distribution. India; Sri Lanka; Malaysia; Singapore; Thailand; Philippines; Greater Sunda Islands, Borneo, Indonesia; and Australia.

Type locality. Patani, Thailand and Penang Island, Malaysia.

Remarks. Kemp (1918) examined the vast number of Decapoda and Stomatopoda collected by Dr. Annadale in Far East and described a new subspecies of freshwater Caridina shrimp namely C. brachydactyla subsp. peninsularis . He ( Kemp 1918) indicated that in great majority of the specimens, 21–37 (mostly 25–32) teeth stretched uninterrupted from the base to the apex on the dorsal margin of the rostrum. Johnson (1963) ignored this defining character and regarded C. b. subsp. peninsularis as a junior synonym of C. simoni . Tiwari and Pillai (1971), who examined specimens referable to C. simoni from Candy, rejected the synonymy of Johnson (1963). They afforded C. n. brachydactyla species status and considered C. b. peninsularis as a subspecies of C. brachydactyla and not a junior synonym of C. simoni .

de Silva (1983) dealt with the distribution of the Sri Lankan Atyidae and considered C. b. peninsularis to be a subspecies of C. simoni while Cai et al. (2007), who examined the type specimens of C. b. peninsularis , rightly accorded full species status to C. peninsularis . Caridina peninsularis differs distinctly from C. simoni in having 20–37 teeth on the dorsal margin of rostrum either uninterrupted or with a distal unarmed margin interrupted by teeth, distal teeth 3–7 spaced (vs. 15–25 proximal teeth leaving 0.25–0.4 of the dorsal margin unarmed distally or interrupted by 1–4 teeth in C. simoni ), 7–22 teeth on the ventral margin either up to the tip or with a short unarmed distal margin (vs. 5–14 teeth proximally on the ventral margin leaving the distal margin always unarmed in C. simoni ), posterior margin of telson broad and moderately triangular with or without median process, bearing 1 pair of lateral spines and 2–3 pairs of long spines of equal length or the median pair fractionally longer than the outer spines (vs. posterior margin broad and rounded, mostly without a median process, bearing 1 pair of long lateral spines and 3–4 pairs sparsely plumose spines that are of equal length or central pair fractionally longer in C. simoni ), possessing ca. 350 eggs of 0.49–0.58× 0.23–0.35 mm size (vs. 50– 160 eggs of 0.65–1.0× 0.45–0.6 mm size in C. simoni ). Based on these characteristics the present study confirms that C. simoni and C. peninsularis are distinct species and the decision by Johnson (1963) to synonymys both species as incorrect.

During the present study, the types of C. mcculochi were examined. Roux (1926b) described C. mccullochi from a number of localities in New South Wales, Australia, including Port Macquarie, Pallal and North Yanco. Of these, the material from the Horton River, Pallal near Bingra and North Yanco are here identified as C. peninsularis . Caridina macculochi specimens from Palal and North Yanco are of 28–31 mm adult size; rostrum equal to antennal scale or shorter; 25–33 teeth on the dorsal margin either evenly up to the tip or with short distal unarmed gap; the distal 3–5 teeth spaced; 2–3 post orbital teeth present; 7–11 teeth on the ventral margin either up to the tip or with a short distal unarmed margin; tip pointed; posterior margin of the telson moderately triangular with or without median process, bearing 1 pair of lateral spines and 3–4 pairs or 7 sparsely plumose spines that are almost equal in length to the lateral spine, endopod of the first male pleopod with a distinct appendix interena, possessing numerous eggs of 0.5–0.58× 0.3–0.35 mm size. These characters indicate that the specimens of C. macculochi from Pallal and North Yanco should be assigned to C. peninsularis . Furthermore, as the specimens from Pallal, Horton River, near Bingara are labelled as types, C. macculochi is here considered to be the junior synonym of C. peninsularis .

Roux (1926a) originally described Caridina meridionalis from 7 localities around New Caledonia and then examined specimens from Sydney, Australia ( Roux 1926b). A single male of 28 mm size from Coindé, New Caledonia appeared different from the type series ( Roux 1926a) and possessed the following characters: rostrum ( Fig. 8a ) slightly shorter than the antennal scale; 30 teeth on dorsal margin compactly up to the pointed tip; 2 post orbital teeth, 8 teeth on the ventral margin proximally leaving a short unarmed margin; rostral formula (2) 30/8; posterior margin of the telson moderately flat with a pair of long lateral spines; 2 pairs of intermediate spines of equal length and equal to the lateral spines and the uropod diaresis spinules numbered 15. This single male differs from Caridina meridionalis in having 30 teeth on the dorsal margin of the rostrum (vs. 19–27) compactly up to the tip, 15 uropod diaeresis spinules (vs. 9–12 diaeresis spinules in C. meridionalis ) posterior margin of the telson without a median process, with 1 pair of lateral spines 2 pairs of intermediate spines that are equal in length to the lateral spines (vs. one pair of lateral spines and 2 pairs of intermediate spines that are shorter than the lateral spines). This single male was consequently identified as C. peninsularis .

Cai & Anker (2004) described and figured a female identified by them as C. peninsularis . Collected in Palawan, Philippines, they considered it was the first record of the species from outside the Malay Peninsula and according to them “This specimen agrees rather well with the description provided by Kemp (1918), although there are some notable differences. For instance, the carpus of the first pereiopod is stouter (1.7 times vs. 2.2–2.6 in the types), while the fingers are shorter (as long as palm vs. 1.5 times as long as palm in the types). Further, the dactylus of the fifth pereiopod is relatively shorter (propodus 4.0 times as long as dactylus vs. 4.8–6.8 times in the types). These differences are tentatively regarded as intraspecific variation, at least until more specimens are collected from the Philippine region”. From Figure 2 ( Cai & Anker 2004) the Philippines female appears to possess 4 spines on the dactylus of the third pereiopod (vs. 6–8 spines in C. peninsularis from the present study) and long lateral spines with 2 pairs of shorter intermediate spines on the posterior margin of the telson with (vs. 2–3 pairs of intermediate spines of equal length to the laterals or the median spines fractionally longer in C. peninsularis from the present study). Consequently the present study does not consider the specimen described by Cai & Anker (2004) as C. peninsularis .

Figures

FIGURE 2. Caridina simoni Bouvier, 1904, NHM 1945. vii. 27.5 – 12, ♂: a) First pereiopod; b) Second pereiopod; c) Third pereiopod; d) Dactylus of the third pereiopod; e) Fifth pereiopod; f) Dactylus of fifth pereiopod; g) First male pleopod; h) endopod of first male pleopod; ♂: i) Endopod of first male pleopod; NHM 1935.5.30.15 – 19, ♀ ovig.: j) First female pleopod; k) Egg. NHM 1945. vii. 27.5 – 12, ♂: l) Second male pleopod; m) Appendix masculina; n) Telson; o) Posterior margin of telson; NHM 1907.1. 7.33, Cotype now Paralectotype, ♀: p) Posterior margin of telson; NHM 1945. vii. 27.5 – 12, ♂: q) Uropod diaeresis spinules; r) Preanal carina.

FIGURE 6. Caridina peninsularis Kemp, 1918, NHM reg. 1919.11.1.12–21, Cotype ♀ ovig.: a) Anterior region of the cephalothorax; ♀: b) Anterior region of the cephalothorax.

FIGURE 7. Caridina peninsularis Kemp, 1918, NHM reg. 1919.11.1.12–21, Cotype ♀ ovig.: a) First pereiopod; b) Second pereiopod; c) Third pereiopod; d) Dactylus of the third pereiopod; e) Fifth pereiopod; f) Dactylus of fifth pereiopod; ♂: g) Endopod of first male pleopod; ♀ ovig.: h) Eggs; ♂: i) Appendix masculina; j) Telson; k) Posterior margin of telson; l) Uropod diaeresis spinules; m) Preanal carina.

FIGURE 8. Caridina peninsularis Kemp, 1918 (was part of type series of Caridina nilotica var. meridionalis Roux, 1926b, NMB 4.VIII.g, Cotype), ♂: a) Anterior region of the cepahalothorax; b) Posterior margin of telson; c) Uropod diaeresis spinules.

FIGURE 9. Caridina peninsularis Kemp, 1918 (was part of type series of Caridina mccullochi Roux 1926a, Cotype) NMB 737a, ♂: a) Anterior region of the cephalothorax; ♂: b) Anterior region of the cephalothorax.

FIGURE 10. Caridina peninsularis Kemp, 1918 (was part of type series of Caridina mccullochi Roux 1926, NHB 737a, Cotype) ♂: a) First pereiopod; b) Second pereiopod; c) Third pereiopod; d) Dactylus of the third pereiopod; e) Fifth pereiopod; f) Dactylus of fifth pereiopod; g) First male pleopod; h) Endopod of first male pleopod; ♀ ovig.: i) Egg; ♂: j) Second male pleopod; k) Appendix masculina; l) Telson; m) Posterior margin of the telson; n) Uropod diaeresis spinules; o) Preanal carina.

FIGURE 6. Caridina peninsularis Kemp, 1918, NHM reg. 1919.11.1.12 – 21, Cotype ♀ ovig.: a) Anterior region of the cephalothorax; ♀: b) Anterior region of the cephalothorax.

FIGURE 7. Caridina peninsularis Kemp, 1918, NHM reg. 1919.11.1.12 – 21, Cotype ♀ ovig.: a) First pereiopod; b) Second pereiopod; c) Third pereiopod; d) Dactylus of the third pereiopod; e) Fifth pereiopod; f) Dactylus of fifth pereiopod; ♂: g) Endopod of first male pleopod; ♀ ovig.: h) Eggs; ♂: i) Appendix masculina; j) Telson; k) Posterior margin of telson; l) Uropod diaeresis spinules; m) Preanal carina.