A New Species Of Siamosquilla From Indonesia (Crustacea : Stomatopoda : Protosquillidae)

3 Pages·1999·1.4 MB·

by  M V Erdmann

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
112(l):94-96. 1999.
A new species of Siamosquilla from Indonesia
(Crustacea: Stomatopoda: Protosquillidae)
Mark V. Erdmann and Raymond B. Manning
(MVE) Department of Integrative Biology, University of California at Berkeley, Berkeley,
California 94720, U.S.A.; (RBM) Department of Invertebrate Zoology, National Museum of
Natural History, Smithsonian Institution, Washington, D.C. 20560-0163, U.S.A.
—
Abstract. Siamosquilla sexava, the second species of the genus, is de-
scribed from Indonesia. It can be distinguished from the type species, S. hyl-
lebergi Naiyanetr, from Thailand, by the shorter median rostral spine, the larger
ocular scales, the much broader telson, and differences in ornamentation of the
fused sixth abdominal somite and telson.
mm
Among the stomatopods collected by one than 20 in adults. Cornea broadened,
ofus (M. V. E.) during a six-year field study set obliquely on stalk. Ocular scales well
in Indonesia was a minute protosquillid developed, produced into triangular lobes
which proved to be the second known spe- laterally, extending nearly to lateral rostral
cies of Siamosquilla Naiyanetr, 1989. It is spine in adults.
described below. Rostral plate sharply trispinous, median
Abbreviations used in the account in- spine distinctly upturned distally, extending
clude: LON, Lembaga Oseanologi Nasional to base of corneas; ventral projection ofros-
(National Institute of Oceanoraphy), Jakar- tral plate large, obtusely rounded ventrally.
ta, Indonesia; TL, total length, measured on Lateral rostral spines extremely long, slen-
the midline; USNM, National Museum of der and recurved, length nearly two-thirds
Natural History, Smithsonian Institution, that of median spine. Basal part of rostral
Washington, D.C, U.S.A. plate very thin. Anterior margins of lateral
The holotype and some paratypes have plates of carapace concave, anterolateral an-
been deposited in the USNM; two paraty- gles strongly produced to a sharp point, ex-
pes are in the LON. tending anteriorly to base of rostral plate.
Mandibular palp absent. Five epipods
Family Protosquillidae Manning, 1980 present.
Siamosquilla Naiyanetr, 1989 Raptorial claw with inflated part of outer
Siamosquilla sexava, new species margin of dactylus notched. Propodus with
single movable spine proximally on inner
Fig. 1
margin.
—
Material examined. Indonesia: Moro- Anterior 4 abdominal somites smooth,
maho, Tukang Besi: 1$, TL 18 mm (ho- unarmed, not carinate dorsally. Fifth ab-
lotype, USNM 260927), 2??, TL 16-17 dominal somite smooth medially, with sin-
—
mm
(paratypes, LON). Gili Meno, Lom- gle low longitudinal carina laterally above
bok: 1(5, TL 17 mm, 1$, TL 18 mm (par- lateral margin, separated from margin by a
USNM
atypes, 260928).—Melanguane, groove, armed with posterolateral spine.
Sangihe-Talaud: 1$, TL 17 mm (paratype, Sixth abdominal somite entirely fused with
USNM
260929).—Taupun, Togian Islands: telson in adults, dorsal surface rough, with
M, TL 13 mm (paratype, USNM 260930). shallow, irregularly curved grooves, lacking
—
Diagnosis. Size very small, TL less carinae entirely.
VOLUME 112, NUMBER 1 95
'^V-^ A
Fig. 1. Siamosquilla sexava, new species, female holotype, TL 18 mm. a. Anterior part ofbody, dorsal view
(apex of left ocular scale damaged); b, Rostral plate, lateral view; c. Fused sixth abdominal somite and telson
and left uropod, dorsal view. Scales = 1 mm.
Telson much wider than long, dorsal sur- opod with 9 short movable spines laterally,
face rough, slightly inflated, with 3 very in- distalmost extending beyond midlength of
distinct bosses. Median boss outlined by a distal segment, with fixed distal spine ven-
shallow groove in dorsal surface of telson; trally. Inner margin of uropodal exopod se-
boss rounded anteriorly, converging poste- tose; uropodal endopod with normal com-
riorly; outline of submedian bosses even plement of setae. Inner spine of basal pro-
less distinct, extending posteriorly almost to longation of uropod much shorter than out-
posterior margin of telson. Median fissure er. —
completely fused, no longer visible. Three Size. Males (n = 2), TL 13-17 mm. Fe-
pairs of marginal teeth, submedians with males (n = —5), TL 13-18 mm.
moveable apices arising submarginally un- Remarks. This small species has a very
der submedian marginal projections. Inter- distinctive rostral plate, with long, recurved
mediate teeth very low and rounded, almost lateral spines, and a telson that is most re-
indistinguishable in larger specimens. Lat- markable for its lack of distinguishing fea-
eral teeth more distinctly produced, with tures; the sixth abdominal somite is fused
rounded apices. Separation between three to the telson, which has almost indiscern-
pairs of marginal telson teeth shallow and ible bosses and a fused median fissure. Sia-
rounded. Submedian teeth with 12-14 den- mosquilla sexava differs from S. hyllebergi
ticles on either side of midline, increasing in numerous features: the median rostral
noticeably in length laterally, intermediate spine is shorter, extending to, rather than
teeth each with 2 fixed mesial denticles, lat- beyond, the cornea and the lateral rostral
erals each with 1 denticle. Lateral margins spines are longer; the ocular scales are
of telson straight, rounded distally. broader; in adults the anterolateral angles of
Uropods stout, proximal segment of ex- the carapace are sharper and more pro-
96 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON
nounced; the dorsal sculpture of the fused Acknowledgements
sixth abdominal somite and telson is much We thank the Indonesian Institute of Sci-
more elaborate; and the telson is much ences for sponsoring Erdmann's project,
broader. and Kalam Sebayang and Ibu Dewi Soen-
The fixed projections on the posterior arijadi for their assistance with research vi-
margin of the telson are much more pro- sas. Dr. Mohammad Kasim Moosa was the
nounced in S. hyllebergi than in S. sexava, Indonesian sponsor of this research, and
and the submedian projections in the former Erdmann gratefully acknowledges his men-
species probably obscure the submarginal, torship on stomatopod morphology and his
We
movable submedian teeth of the telson, continual support of this project. also
which are clearly visible in 5. sexava. thank Dr. Sukarno, Dr. Suharsono, and Dr.
In 5". sexava, the size of the ocular scales Anugerah Nontji of the Indonesian Institute
of Sciences.
increases allometrically, and in very small
Funding for Erdmann's research was pro-
specimens of S. sexava the scales resemble
vided by grants from the UC Pacific Rim
those of larger S. hyllebergii; they increase
Research Program, the NSF International
in width with increasing TL.
— DDIG (#9503060 and #9704616) Program
Distribution. Known only from eastern
and a visiting scientist appointment from
Indonesia, where it is relatively widespread. the Smithsonian Institution. Lilly King
Recorded from five regions: Lombok, San-
Manning prepared the figure. This is con-
gihe-Talaud, Togian Islands, and Tukang tribution no. 467 from the Smithsonian Ma-
Besi Archipelago.
— rine Station at Fort Pierce, Florida; the sup-
Etymology. The species name is from port of that program for Manning's studies
the word sexava, which means "mantis" in of stomatopod systematics is gratefully ac-
Bahasa Talaud, the local language in one of knowledged. We gratefully acknowledge
the collection localities (Melanguane, San- the reviews of Shane Ahyong, David K.
gihe-Talaud). The local fishermen, school Camp, and Roy K. Kropp as well as the
teachers and children there were most help- cooperation of Rafael Lemaitre.
ful in assisting with collecting, and were
Literature Cited
fully cognizant of the differences between
stomatopods and other decapod shrimp, Naiyanetr, P. 1989. Siamosquilla hyllebergi, a new ge-
comparing stomatopods to the "sexava" nus and new species of stomatopod from Thai-
land. In E. A. Ferrero, ed., Biology of stomato-
without any solicitation. Their assistance is pods. Selected symposia and monographs,
most appreciated. U.Z.I., 3:281-284. Muchi, Modena.