Crinotonia anastasiae, Marin, 2006

Marin, Ivan, 2006, Description Of Crinotonia Anastasiae, New Genus, New Species, A New Crinoid Associated Pontoniine Shrimp (Crustacea: Caridea) From Nha Trang Bay, Vietnam, With Inclusion Of Periclimenes Attenuatus Bruce, 1971, In The New Genus, Raffles Bulletin of Zoology 54 (2), pp. 321-340 : 322-329

publication ID	https://doi.org/ 10.5281/zenodo.13245398
persistent identifier	https://treatment.plazi.org/id/03BFCE58-FFED-FFBC-15EB-FBFF1B347F68
treatment provided by	Felipe
scientific name	Crinotonia anastasiae
status	sp. nov.

Treatment

Crinotonia anastasiae View in CoL , new species

( Figs. 1-6 View Fig )

Material examined. – Holotype: ovigerous female (PCL 3.8 mm)( ZMMU Ma 5459), South China Sea , Vietnam, Nha Trang Bay, Mun Island, depth 10-12 m., from crinoid Phanogenia gracilis , coll. I. Marin, 24 May.2004.

Allotype: male (PCL 2.6 mm)( ZMMU Ma 5460), same data as holotype.

Description. – Holotype female. Carapace swollen, smooth, with antennal and hepatic spines. Hepatic spine is distinctly smaller than antennal and directed horizontally. Rostrum short, straight, tapering and slightly compressed, with developed dorsal carina bearing four conspicuous teeth, without ventral teeth and ventral carina ( Fig. 2a, b); lateral lamina feebly developed, continuous with orbital margin posteriorly ( Fig. 2c, d). Orbit feebly developed, inferior orbital angle rounded, slightly projecting. Pterygostomial margin bluntly angular.

Abdominal somites smooth; pleura of first to fifth abdominal somites rounded, postero-lateral angle of sixth abdominal somite is broad and pointed, postero-ventral angle projecting and rounded ( Fig. 6a, b View Fig ). Telson is about three times as long as wide ( Fig. 6b View Fig ), converge gradually posteriorly, with two pairs of conspicuous dorsal submarginal spines situated at 0.4 and 0.7 of telson length; three pairs of posterior spines contain short lateral, long and slender intermediate and slender submediate spines which are about half of intermediate spine length ( Fig. 6e View Fig ).

Eyes large and well developed, with slightly projecting cornea. Central cornea with small papilla.

Antennules ( Fig. 2e,f) well developed; basal segment is about two times longer than wide, with lateral border bearing an acute distolateral tooth, distal medial lobe with acute medial tooth, small setae is presented between teeth; distinct robust ventral tooth is situated on the middle of medial border of basal segment. The stylocerite is well developed. The intermediate segment is slender, about 1.5 times as long as wide, with disto-lateral inner border produced distally. The distal segment is about two times as long as wide. The upper flagellum with rami fused for the two proximal segments, the shorter ramus consists of four segments with five groups of aesthetascs, and the longer free ramus consists of more than twenty segments. The lower flagellum is filiform with more than twenty segments.

Antenna ( Fig. 2h) well developed stylocerite, basicerite with small disto-ventral tooth; carpocerite is slender, about four times as long as wide; flagellum is well developed, with the length equal to body length; scaphocerite is slender and exceeding the distal margin and intermediate antennular segment, about 3 times as long as maximum width, with well developed distolateral tooth.

Mouthparts without special features. Mandible ( Fig. 3a View Fig ) without palp; incisor process tapering to acute point with two terminal teeth; molar process well developed, robust, with five stout tooth distally.

Maxillula ( Fig. 3b View Fig ) is normal, with well developed bilobed palp; the upper lacinia is slightly curved, flaring distally, with strong setae distally; the lower lacinia is slender, tapering distally.

Maxilla ( Fig. 3c View Fig ) with well developed simple palp; endites are well developed, basal endite feebly bilobed, distal lobes subequal, furnished with stiff, elongated setae; scaphognathite well developed, with plumose setae.

First maxilliped ( Fig. 3d View Fig ) with distinct and well developed endites, basal endite is significantly larger, with setae along lateral margin; exopod well developed with large caridean lobe bearing plumose setae; epipod is triangular in shape, well developed.

Second maxilliped ( Fig. 3e View Fig ) with exopod well developed; distolateral margin of propodus broadly rounded, with slender setae; dactylus about three times longer than broad, with numerous spines along distal margin; epipod subrectangular; podobranch absent.

Third maxilliped ( Fig. 3f View Fig ) with slender segments and well developed exopod exceeding the length of ischiomerus; ischiomerus is about 3.5 times as long as maximum width, tapering significantly distally, the penultimate segment is slender, about five times as long as wide; the terminal segment is also slender, about seven times as long as wide, with sparse long setae along the border; epipod oval; arthrobranch absent.

First pereiopod ( Fig. 4a View Fig ) slender, with robust chela and broad, swollen fingers; carpus is slender, significantly flaring distally, palm is equal in width and length, slightly compressed laterally; fixed finger is robust with numerous terminal setae, with acute tip and feebly developed cutting edge; dactylus with acute tip and, subcylindrical, without conspicuous cutting edge ( Fig. 4b,c View Fig ).

Second pereiopod highly differ in size and shape. Major pereiopod ( Fig. 4d View Fig ) with robust segments; ischium is about two times as long as wide; merus is about 3.4 times as long as maximal width, with medial part swollen centrally; carpus is flared distally, as long as maximal width, palm is subcylindrical, about 2.5 times as long as maximal width; fingers with acute, curved tips; fixed fingers robust, with two teeth opposing into deep pits on the dactylus, with distinct cutting edge on distal third of the length; dactylus is robust, about 4.5 times as long as wide, with distinct dorso-lateral flange along the proximal two-third of the length, ventral margin with distinct protruding cutting edge in distal third of the length, with two mesial deep pits and one tooth in proximal third of the length ( Fig. 4 View Fig a-d). Minor pereiopod ( Fig. 4e View Fig ) is extremely slender, ischium is about eight times as long as wide; merus is about thirteen times as long as width; carpus is flared distally, about fifteen times as long as maximal width, palm is subcylindrical, about five times as long as width, slightly tapering distally, fingers are slender, subcylindrical, equal to palm length, about 2.5 times as long as proximal width, with pointed, curved tips ( Fig. 4f View Fig ).

Third pereiopod ( Fig. 4g View Fig ) slender, with unarmed segments; ischium is about 3.5 times as long as wide; merus is about seven times as long as wide; carpus is about 3.5 times as long as maximum wide, tapering proximally; propodus is about 10.5 times as long as wide, with serrated ventral margin ( Fig. 4h View Fig ); dactylus ( Fig. 4i View Fig ) slender, about 3 times as long as maximum width, significantly tapering distally, biunguiculate, with pointed slender curved unguis and preterminal triangular accessory tooth directed distally ( Fig. 4j View Fig ). Fourth and fifth pereiopods are similar.

Pleopods are normal, endopod of second pleopods in male with developed appendix masculina bearing numerous long terminal spines ( Fig. 6f View Fig ). Uropods ( Fig. 6c View Fig ) slender, exceeding telson; lateral border of uropodal endopod with small distal tooth and mobile spine.

Remarks. – An unique feature, presence of three well developed submediate posterior spines, was found in allotype specimen ( Figs. 6f, g View Fig ). The holotype specimen possesses two submediate posterior spines ( Fig. 6h View Fig ) that is ordinary normal in the Pontoniinae . This feature of the allotype is considered as an individual variation, but it needs confirmation on further material.

Colour in life. – Unknown.

Etymology. – This species named in honour of Anastasia Abramkina.

Distribution. – Known only from type locality, Nha Trang Bay, Vietnam.

Differential diagnosis. – Crinotonia anastasiae , new species,

is most similar to P. attenuatus but clearly differs in having a more robust body and appendages (segments of antennules and antenna (scaphocerite), second pereiopods, especially the palm of the major cheliped, and the walking legs), the more developed rostral carina, especially in the female, the form of distal part of dactylus of third pereiopod and the presence of several denticles along its ventral border.

Host and associated fauna. – Specimens were found on comatulid crinoid Phanogenia gracilis ( Comasteridae : Crinoidea) also harbored with three juveniles of eumedonid crabs Harrovia sp.

Crinotonia attenuatus ( Bruce, 1971) , new combination

( Figs. 7-10 View Fig )

Periclimenes attenuatus Bruce, 1971: 533 View in CoL , Figs. 1-5 View Fig [type locality: Waterhouse Cove, Burukuk, Duke of York Group, Bismark Archipelago, associated with crinoids in 1-2 meters]; Bruce, 1983a: 879; 1983b: 206; Chace & Bruce, 1993: 103; Müller, 1993: 71; De Grave, 2000: 134; Li, 2000: 159, Fig. 196; 2004: 68, Figs. 1 View Fig , 2.

Material examined. – 1 ovigerous female (PCL 4.2 mm)( ZMMU Ma 5461), 1 male (PCL 3.2 mm)( ZMMU Ma 5462), South China Sea , Vietnam, Nha Trang Bay, Mun Island, depth 10-15 m, from crinoid Phanogenia gracilis , coll. I. Marin, 6 Oct.2003; 1 ovigerous female (PCL 3.8 mm)( ZMMU Ma 5463), 1 male (PCL 2.3 mm)( ZMMU Ma 5464), from crinoid Phanogenia gracilis , same locality as previous ; 1 male (PCL 3.2 mm)( ZMMU Ma 5465), from unidentified comatulid crinoid, same locality as previous .

Description. – Body is slender. Carapace smooth, swollen, with antennal and small hepatic spines. Rostrum ( Fig. 8 a-d) short, tapering, slightly upturned, with three-four dorsal teeth only, dorsal lamina is feebly developed, ventral teeth absent, lateral lamina feebly developed. Pterygostomial margin bluntly angular. Abdominal somites smooth; pleura of first to fifth abdominal somites rounded, postero-lateral angle of sixth abdominal somite pointed and postero-ventral angle projecting and rounded ( Fig. 9i). Telson about three times as long as wide, with two pairs of dorsal and three pairs of posterior spines ( Fig. 9j). Eyes slightly projecting distally, with corneal papillae. Antennules with large disto-lateral tooth and small teeth on distal medial lobe on proximal segment, robust ventral tooth in middle of medial border of basal segment ( Fig. 8h,g). Antenna ( Fig. 8k) with slender, about 4.5 times as long as maximum width. Second maxilliped without podobranch. First pereiopod ( Fig. 9a) slender, with robust chela and broad, swollen fingers bearing numerous setae. Major second pereiopod ( Fig. 9b) with slender, subcylindrical palm about 4 times as long as wide; minor pereiopod ( Fig. 9d) is extremely slender, with simple slender fingers. Third pereiopod ( Fig. 9f) with unarmed segments; ischium is about 5.5 times as long as wide; merus is about thirteen times as long as wide; carpus is about seven times as long as maximum wide, tapering proximally; propodus is about 11.5 times as long as wide, with serrated ventral margin; dactylus ( Fig. 9g) is slender, about three times as long as maximal width, significantly tapering distally, preterminal accessory tooth is triangular and situated perpendicularly to ventral margin ( Fig. 9h).

Remarks. – The observed specimens are identical to Bruce’s (1971) original description. However, Li (2004) showed podobranch in material from Indonesia. The rostral formula in Vietnamese material is 3-4/0 and similar to Bruce’s material. Li (2004) reported the presence of tiny sub-apical ventral tooth on rostrum and a “podobranch” on the second maxilliped and absence of epipod on the first maxilliped. During the material dissection I also received the same situation when epipod of first maxilliped was dissected together with second maxilliped attaching to it anteriorly. It looks like “podobranch” of second maxilliped while first maxilliped missing its epipod.

One of specimens studied (male, PCL 2.3 mm) ( Fig. 10 View Fig ) shows the presence of a large disto-lateral tooth and three (large and two small) mesial teeth on the disto-medial border of basal segment of the antennules ( Fig. 8i) that is slightly differ from type material. Minimal PCL of observed ovigerous females is 2.5 mm, for males – 2.0 mm and reaches to 4.2 mm and 3.2 mm respectively that significantly increase the known size of the species.

Colour in life. – Unknown.

Hosts. – In Nha Trang Bay, this species was found exclusively on the crinoid Phanogenia gracilis .

Distribution. – Known from Indonesia, Vietnam, Papua New Guinea and Palau.

Taxonomy. – The diagnosis of the genus Periclimenes with the type species P. amethysteus (Risso, 1827) from the Mediterranean Sea includes a well developed rostrum bearing robust dorsal and ventral teeth, second maxilliped with podobranch, small arthrobranch on third maxilliped, slender first pereiopod with simple fingers; similar second pereiopods with chelae not borne in vertical plane, movable finger not ventral, finger without socket and plunger closure, third pereiopod with ventral margin of propodus smooth, with disto-ventral spines, dactylus distinctly biunguiculate ( Holthuis, 1952; Chace & Bruce, 1993). Crinotonia attenuatus (Bruce) , new combination, shows many differences from the genus Periclimenes Costa, and its inclusion into a new genus is justified. The species is more similar to Crinotonia anastasiae , new species, than to any species of genus Periclimenes with regards to the features reported in diagnosis of Crinotonia , new genus.