Redefinition Of Betaeopsis Yaldwyn, 1971, And Invalidation Of Hamalpheus Bruce & Iliffe, 1991 (Crustacea : Decapoda : Alpheidae)

15 Pages·2002·4.8 MB·English

by  A Anker

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
115(3):570-584. 2002.
Redefinition of Betaeopsis Yaldwyn, 1971, and invalidation of
&
Hamalpheus Bruce Iliffe, 1991 (Crustacea: Decapoda: Alpheidae)
Arthur Anker and Ming-Shiou Jeng
(AA) Laboratoire des Invertebres Marins et Malacologie, Museum National d'Histoire Naturelle,
55, rue de Buffon, 75005 Paris, France, e-mail: [email protected];
(MSJ) Institute of Zoology, Academia Sinica, Nankang, Taipei, Taiwan 11529, R.O.C.,
e-mail: [email protected]
—
Abstract. The poorly known alpheid shrimp Betaeopsis indicus (De Man),
originally described from Lombok, Indonesia, is reported here for the first time
from the waters of Taiwan and northern Australia. Examination of the new
material has shown that the monotypic Hamalpheus Bruce & Iliffe, is ajunior
synonym of Betaeopsis Yaldwyn. Three ofthe four diagnostic features used to
separate Hamalpheus from other alpheid genera, are present in both B. indicus
and the type species B. aequimanus (Dana). These features include the peculiar
hook-like spines on the uropods. Betaeopsis, now containing three species, is
redefined, while detailed redescriptions and synonymies are provided for B.
aequimanus and B. indicus. The relationships of Betaeopsis to Betaeus Dana
are discussed.
The type description of the alpheid this feature is Hamalpheusacanthops Bruce
&
shrimp Betaeopsis indicus (De Man, 1910, Iliffe, 1991, described on the basis of a
as Betaeus indicus), was based on two spec- single female specimen collected in a ma-
imens, an ovigerous female and a young in- rine lava tube on Upolu Island, Samoa. This
dividual, collected by the Siboga Expedi- discovery prompted the rexamination of
tion in Lombok, Indonesia. Subsequently, both genera.
B. indicus was recorded in the Red Sea by We examined the majority of known
&
Banner Banner (1981), and in the Phil- specimens of B. indicus and H. acanthops,
ippines by Chace (1988), each time accom- including type-specimens of both species.
panied by short comments and without il- Also examined were specimens ofBetaeop-
lustrations. sis aequimanus (Dana, 1852), the only oth-
In January-February 1999 one of us er species of the genus Betaeopsis Yald-
(AA) studied the alpheid collection at the wyn, 1971 and its type species. All these
National Museum of Natural History, specimens were found to bear the hook-like
Smithsonian Institution, Washington, D.C. spines on the uropods. Furthermore, both
and examined a large male specimen from species of Betaeopsis share two features
Ch'uan-fan-shih, Taiwan, carrying a label considered as diagnostic for Hamalpheus
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''Betaeus sp." This specimen presented all (cf. Bruce Iliffe 1991): the inner spines
characters of Betaeopsis indicus, as de- of the posterior margin of telson slightly
scribed by De Man (1910), but furthermore curved upwards, and the presence of strong
it was found to have two conspicious hook- acute projections on the eyestalks. The only
like spines on the tip of the uropodal en- character remaining which separates H.
dopod. This unusual feature was not men- acanthops and B. indicus is the absence of
tioned in De Man's original description. dorsal spines on the telson in the former
The only alpheid species known to present species, a character not considered to be of
.
VOLUME 115, NUMBER 3 571
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Table 1. The branchial formula summary ofBetaeopsis Yaldwyn, 1971
Mxpl Mxp2 Mxp3 PI P2 P3 P4 P5
Pleurobranchs 1 1 1 1 1
Arthrobranchs 1
Podobranch
Mastigobranch 1 1 1
Setobranchs + + +
Exopods
1 1 1
generic importance. Hence Hamalpheus is tylus ventral; outer face of palm smooth,
placed in the synonymy of Betaeopsis. Be- mesial face with blunt tubercles; cutting
taeopsis is redefined, and redescriptions are edges of chela with irregular teeth, lacking
provided for B. aequimanus and B. indicus. snapping mechanism. Second pereiopods
with carpus 5-segmented. Third pereiopods
Material and Methods with or without movable spine on inferior
margin of merus; dactylus biunguiculate.
The material ex,amined remains deposit-
Articulated plate on sixth abdominal seg-
ed in the National Museum of Natural His-
ment absent. Second male pleopod with ap-
tory, Smithsonian Institution, Washington,
pendix interna and appendix masculina.
D.C., U.S.A. (USNM); Northern Territory
Uropodal endopod with 2 hook-like spines
Museum, Darwin, Australia (NTM);
on distal margin. Telson with or without
Queensland Museum, Brisbane, Australia
(QM); Naturhistoriches Museum Wien, dorsal spines; posterior margin laterally
Austria (NHMW); Zoological Museum, with 2 subequal spines, inner curved up-
wards. Anal tubercles absent. Branchial for-
University of Amsterdam, Netherlands
(ZMU); and Nationaal Natuurhistorisch mula summarized—in Table 1.
Type species. Betaeopsis aequimanus
Museum, Leiden, Netherlands (RMNH).
(Dana, 1852), by original designation
All measurements and scales are in milli-
(Yaldwyn, 1971:8—8)
meters. Abbreviations used in the text as
following: TL = total length; CL = cara- Other species. B. indicus (D&e Man,
pace length; Mxp = maxilliped; P = pe- 1910), and B. acanthops (Bruce Iliffe,
reiopod. 1991), new—combination.
Remarks. Several important characters
have been added to the generic diagnosis of
Family Alpheidae Rafinesque, 1815
Betaeopsis, the most important being the
Betaeopsis Yaldwyn, 1971
Hamalpheus—Bruce & Iliffe, 1991: 583. pdroepsoedncoefoufrotphoed.hoBorku-lcieke&sIpliifnfees(o1n99t1h)eleisnt--
Diagnosis. Body not strongly com- ed several characters shared by Betaeopsis
pressed. Carapace smooth; frontal region (now including Hamalpheus) and Betaeus:
without rostrum or orbital teeth; pterygos- absence of rostrum and orbital teeth; eyes
tomial angle rounded. Eyes concealed in completely covered by frontal projection of
dorsal view, visible in frontal view; cornea carapace; first pereiopods with chelae car-
well developed; eyestalks with strong an- ried extended, with dactylus in ventral po-
teriorprocesses between cornea and median sition; fingers of chelae lacking molar pro-
margin. Outer antennular flagellum bira- cess and fossa; second pereiopods with 5-
mous. Mandible with palp. Ultimate seg- segmented carpus; robust ambulatory pe-
ment of third maxilliped distally armed reiopods, only first and second with
with small spine. First pereiopods subsym- epipods; diaresis of uropodal exopod non-
metrical, equal, carried extended with dac- denticulate. However, several other alpheid
—
572 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
genera, not closely related to Betaeopsis or middle of corneas (cf. Coutiere 1899:65-
Betaeus, are characterized by the absence 67, figs. 9-13), triangular in dorsal and
of rostrum and snapping mechanism, have frontal views. Orbital hoods completely
dorsally concealed eyes, five-segmented covering eyes in dorsal view, but open an-
carpus and inverted first chela. The last two teriorly. Eyes partially visible in lateral
&
characteristics listed by Bruce Iliffe view. Anterior margins of each eyestalk
(1991) are not exact. We examined most with strong, acute process visible in lateral
species of Betaeus and found that at least aspect of frontal region (Fig. 2A). Ocellar
eight of them have strap-like epipods on beak produced in a strong, acute tooth, well
first to fourth pereiopods, and not only on visible in dorsal and frontal view. Ptery-
first and second. Also, the transverse suture gostomial region rounded; branchiostegial
in many Betaeus species is denticulate margin ofcarapace with weak emargination
(finely toothed). above first and second pereiopods (Fig.
Betaeopsis can be separated from Be- 2H).
taeus by the presence of uropodal hooks; Antennular peduncle robust; first anten-
the reduced number of epipods; the shape nular article with strong styloceritereaching
of the diaresis (non denticulate in Betaeop- distal half of second article or third article,
sis vs. finely denticulate in most species of and with shallow depression proximal to
Betaeus); the absence of the articulated distal margin (Fig. 2C); medio-ventral mar-
plate on sixth abdominal somite; and the gin with strong acute carina (Fig. 2C); sec-
absence of anal tubercles. ond article shorter than first, and slightly
longer than third; external antennular fla-
Betaeopsis aequimanus (Dana, 1852) gellum biramous, bifurcating at twelfth seg-
Figs. lA, 2-5 ment in largest specimen. Antennae robust;
basicerite stout, with large ventro-lateral
Betaeus aequimanus Dana, 1852a (con-
spectus): 23.—1852b: 560.—1855 (at- tooth; carpocerite exceeding both scapho-
las), pi. 35, fig. 11.—Miers, 1876: 83.— cerite and antennular peduncles; scaphocer-
Filhol, 1885: 433.—Coutiere, 1896: ite broadly ovate (Fig. 2B), with strong lat-
384.-1899 (see Chace & Forest, 1970, eral spine reaching to anteriormargin ofan-
tennular peduncle; antennal flagellum long,
for full page and figure numbers).
Thomson, 19&03: 438, pi. 28, figs. 1, 2.— verMyourtohbpuasrttasndtyfpliactatlenefdo.r Alpheidae (Fig.
Richardson Yaldvv'yn, 1958: 37, fig. 36
4); mandible with incisor process bearing 5
(in key).—Zarenkov, —1968: 194. strong teeth, a 2-jointed palp, and molar
Betaeopsis aequimanus Yaldwyn, 1971:
process with semicircular rows of setae;
88.
— maxillule with bilobed palp, both lobes with
Materialexamined. 3 males (largestCL slender plumose setae; maxilla with small
7.2 mm). Palm Beach, Waiheke Isl., south- palp and deeply notched upper lacinia; first
ern Hauraki Gulf, North Island, New Zea- maxilliped with weakly developed caridean
land, USNM 10734. 1 male (CL 4.8 mm, lobe; second maxilliped with very long ex-
TL 16 mm), Te Onepoto, North Island, coll. opod and triangular epipod. Third maxilli-
NHMW
and depth unknow—n, 955. ped not exceeding antennal peduncle; coxa
Redes—cription. Medium-sized alpheid with acute lateral plate above strap-like epi-
shrimp maximum TL about 32 mm pod (Fig. 5C); exopod almost reaching pen-
(Thompson 1903, Richardson & Yaldwyn ultimate segment of endopod; antepenulti-
1958). Carapace smooth, dorsal region with mate segment slender, longer than penulti-
very short and scarce setae; frontal region mate and ultimate segments together; ulti-
with deep subacute, dorso-median incision mate segment with numerous rows of
(Fig. 2B) extending posteriorly to about strong setae and with 1 apical spinule; ar-
VOLUME 115, NUMBER 3 573
Fig. 1. A, Betaeopsis aequimanus (Dana, 1852). Male, USNM 10734; B, Hamalpheus acanthops Bruce &
Iliffe 1991. Female holotype (after Bruce & Iliffe 1991).
throbranch rather feebly developed, with 4 teeth (Fig. 3B and Coutiere 1899:188, figs.
or 5 branchial leaflets (Fig. 5A). 222-226); chelae slightly enlarged, with
First pereiopods almost symmetrical and dactylus situated in ventral position; palm
equal in size, carried extended and slightly about 1.7 times longer than dactylus; lateral
twisted mesially (Fig. 3); coxa bearing a side of palm smooth, mesial side bearing
strap-like epipod; ischium without special row of small tubercles (Fig. 3B); fixed fin-
features; merus as long as palm, triangular ger with elongated, curly setae on margin
in cross-section, superior and lateral mar- (Fig. 3C); cutting edges armed with small
gins terminating each by distal tooth; car- irregular teeth (Fig. 3D).
pus short, cup-shaped, with 3 blunt distal Second pereiopods as long as first che-
574 PROCEEDINGS OF THEBIOLOGICAL SOCIETY OF WASHINGTON
Fig. 2. Betaeopsis aequimanus (Dana, 1852). Male, USNM 10734. A, frontal region, lateral view; B, same,
dorsal view; —C, antennule: stylocerite and car—ina; D, branchiostegia—l margin from third—maxilliped to third
pereiopod, ep epipod (mastigobranch), Mxp3 third maxilliped, PI first pereiopod, P3 third pereiopod; E,
second pleopod; F, same, appendix interna and appendix masculina; G, telson and left uropod: H, uropod. lateral
spine; I, same, tip ofendopod; J, telson, posterior margin.
lipeds when fully extended; coxa with a proximately equal to: 4.7 : 1.0 : 1.0 : 1.0 :
strap-like epipod; carpus 5-jointed, proxi- 2.4 (Fig. 3E); chelae simple, with unarmed
mal article nearly as long as four following cutting edges; palm as long as distal carpal
combined, proportions ofcarpal articles ap- article and about 1.6 times longer than dac-
VOLUME 115, NUMBER 3 575
mm
1
Fig. 3. Betaeopsis aequimanus (Dana, 1852). Male, USNM 10734. A, first pereiopod, outer and ventral
view; B, same, dorsal view; C, same, inner view; D, same, fingers; E, second pereiopod, carpus.
tylus; fixed finger and dactylus with nu- pereiopod with slightly different propor-
merous thickened setae. Third pereiopod tions of articles (merus relatively shorter,
robust (Fig. 5D); coxa with setobranchs propodus longer. Fig. 5F); spinulation of
only; following articles somewhat com- propodus reduced to 4 or 5 spines, includ-
pressed; ischium unarmed; merus armed ing distal pair of curved spines; brush on
with strong spine on proximal inferior mar- distal portion of propodus composed of 3
gin (Fig. 5D); carpus with superior projec- rows of short setae (Fig. 5G).
tion above carpo-propodal articulation, and Abdomen smooth, pleura 1-4 ventrally
small distal spine on inferior margin; pro- rounded, fifth pleuron with acute ventro-
podus armed with 6 to 8 small, paired or posterior angle. Ventral posterior margin of
unpaired spines, and 2 stronger, curved dis- sixth abdominal segment with acute median
tal spines proximal to dactylar articulation; tooth. Uropods reaching far beyond telson,
dactylus biunguiculate, secondary unguis sparsely covered by fine setae; exopod with
acute, situated on distal portion of inferior strong lateral spine and well marked, thick-
margin. Fourth pereiopod similar to third, ened diaresis; tip of endopod with 2 strong,
less robust and without setobranchs. Fifth ventrally curved spines. Telson broad.
576 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
—Fig. 4. Betaeopsis aequiinaiuis (Dana, 1852). Male, USNM 10734. Right mouthpart.s in outer view (except
A inner view). A, mandible; B, maxillula; C, maxilla; D, first maxilliped; E, second maxilliped.
VOLUME 115, NUMBER 3 577
BCEG
Fig. 5. Betaeopsis aequimanus (Dana, 1852). Male, USNM 10734. A, third maxilliped; B, same, tip of
ultimate segment; C, same, lateral plate, epipod and arthrobranch; D, third pereiopod; E, same, distal portion of
propodus and dactylus; F, fifth pereiopod; G, same, distal portion ofpropodus and dactylus.
578 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
—
slightly tapering, with a shallow, medio- Material examined. Syntypes: 1 ovig-
dorsal, longitudinal groove, and two pairs erous female (CL 6.2, TL 20) and 1 young
of strong dorsal spines; posterior margin specimen, (CL 4.5, TL 14.5), Anchorage
with lateral parts somewhat angular and off Labuan Pandan, Lombok, Indonesia,
median part rounded; 2 pairs of subequal, sta. 34, 27 March (year not given), 18 m,
short, blunt spines, inner being slightly coral reef, ZMU De102776.-1 male (CL
curved upwards (right outer spine missing 5.6), 09°03'08"N, 122°59'30"E, Maloh, Ne-
in one sp—ecimen, cf. Fig. 2J). gros, Visayan Islands, Philippines, S.O.S.C.
Color. According to Thomson (1903: coll., 13 May 1978, poison, 0-1 m, USNM
439): "the specimens from Stewart Island, 213508.-1 male (CL 10, TL 27), label
taken under stones, were of a uniform "Betaues sp.?", rocky shore, Ch'uan-fan-
brownish-red colour; those from Moeraki, shih, Taiwan, 2r55'8N, 120°49'E, sta.
caught on the seaweed, were olive-green." VGS 68-21, coll. V. G. Springer, J. H.
Richardson & Yaldwyn (1958) noted the Choat, C. W. Yen, 7 May, 1968, to 13 m,
color as "orange-yellow or dark green with USNM 362219.-1 female (CL 5.1, TL
dorsal light-colou—red band". 15), 12°31'8"S,NW123°33'2"E, Cartier Reef,
Type material. Dana's (1852) types col- Timor Sea, off Australia, coll. J. Short,
lected in the Bay ofIslands are probably no sta. Ca-09, 5 May 1992, marine reef, under
QM
more extant. — Wbeach r—ock boulders, on sand,
Distribution. Restricted to temperate 17551. 5 specimens (not measured and
waters of New Zealand and neighbouring sexed), Cundabilu Islands, Dahlak Archi-
islands. Reported from Bay ofIslands, Wai- pelago, SW Red Sea, rocky eastern shore,
wera, Cape Campbell, Moeraki, Dunedin, with sand patches and corals, at 1-2 m, coll.
Stewart Island, Chatham Islands (Thomson E62 (First Israeli South Red Sea Expedi-
1903, Richardson & Yaldwyn 1958), Cook tion, Tel Aviv University), 20 March 1962,
Strait (Filhol 1885), Waiheke Island off RMNH. —
Auckland. Redescription. Medium-sized alpheid
—
Habitat and biology. Found in coastal shrimp (TL 15-27 mm). Carapace smooth,
shallow waters, "most commonly under with some sparse setae; frontal region with
stones or among weed between tide-marks, shallow median emargination (Fig. 6B).
less rarely in rock-pools" (Thomson 1903). Eyes dorsally concealed completely by or-
Thomson also noted that "the normal mode bital hoods, not visible in lateral view, well
of progression appears to be walking, but visible in frontal view. Anterior margins of
when disturbed the animal escapes by vig- each eyestalk with strong, acute process
orous leaps of a foot or more in length." (Fig. 6C). Ocellary beak well developed.
The shrimps may be often found in damp Pterygostomial region rounded; branchios-
situations out of water, and are capable of tegial margin with very shallow sinus
jumping like littoral amphipods. Ovigerous above first and second pereiopods.
females are found from August to at least Antennule with well developed stylocer-
January (Richardson & Yaldwyn 1958). ite reaching to midlength of second article;
antennular carina as illustrated (Fig. 7E);
Betaeopsis indiciis (De Man, 1910) outer antennular flagellum bifurcating at
Figs. 6, 7 ninth-twelfth segment; antenna with robust
flagellum (Fig. 68); basicerite with acute
Betaeus indicus De Man, 1910: 309; 1911: ventro-lateral tooth; scaphocerite ovate,
173; 1915 (atlas): pis. 4, 5, fig. 15.— reaching distal part of third antennulai" ar-
Yaldwyn, 1971: 88.—D. M. & A. H. ticle, bearing strong lateral spine (Fig. 6B);
Banner, 1981: 48.—D. M. & A. H. Ban- caipocerite of antenna exceeding both sca-
ner, 1985: 35.—Chace, 1988: 69. phocerite and antennulai"peduncles. Mouth-
VOLUME 115, NUMBER 3 579
—
Fig. 6. Betaeopsisindicus(DeMan, 1910). A-H, syntype,female,ZMU Del0277; B,frontalregion,dorsal
view (after De Man 1910); C, same, lateral view; D, first pereiopod; E, second pereiopod; F, third pereiopod;
G, same, dactylus; H, egg.
parts typical for genus. Third maxilliped larged (Fig. 6C); merus slightly shorterthan
when extended, not exceeding antennal pe- palm, more or less triangular in cross-sec-
duncles; exopod not reaching penultimate tion, with weak apical tooth on superior
segment; arthrobranch weakly developed. margin and blunt apical tooth on lateral
First pereiopods robust, with chela en- margin; carpus with rounded distal teeth;