A 'swimming' Heteropoda species from Borneo (Araneae, Sparassidae, Heteropodinae).
Keywords: Sparassidae, Heteropoda, taxonomy, new species, Borneo
The sparassid subfamily Heteropodinae includes eight genera, of which Heteropoda Latreille 1804 is by far the most diverse with about 190 nominal species (Jager 2002). The genus has not been revised in recent times except for the species from the Australian region (Davies 1994).
In 1998 Satie Airame and Petra Sierwald observed and collected specimens of an unidentified Heteropoda species in a lowland rainforest on Borneo (Malaysia, Sabah). Individuals were observed in a laboratory and the hunting behavior was investigated. Hunting on the water surface could be shown the first time for the family Sparassidae. Even though the observations were made under artificial conditions, there is evidence that this behavior also occurs in natural situations (Airame & Sierwald 2000).
Two Heteropoda species have been described previously from Borneo: H. hosei Pocock 1897 and H. obtusa Thorell 1890. After comparing the new material with type material and original descriptions, it appeared to be a species new to science, which is described below. Conspecifity of H. obtusa with the here described new species can be excluded by the distinctly smaller size of H. obtusa (ca. 14.5 mm body length: Thorell 1890). As H. hosei could be confused with the new species due to similar size, it is diagnosed and illustrated below.
Specimens are deposited in the Field Museum of Natural History Chicago, USA (FMNH), Forschungsinstitut und Naturmuseum Senckenberg, Germany (SMF) and the Natural History Museum London, England (BMNH). Format and style of description as well as treatment of female genitalia follow Davies (1994) and Jager (2000). Measurements are expressed in millimeters. Measurements of appendages are listed as: total length (femur, patella, tibia, metatarsus, tarsus). Arising points of tegular parts (i.e. embolus, conductor) are described for the left palp in a ventral view.
Abbreviations. ALE = anterior lateral eyes, AME = anterior median eyes, AW = anterior width of dorsal shield of prosoma, CH = clypeus height, FE = femur, MT = metatarsus, OL = opisthosoma length, OW = opisthosoma width, PA = patella, PH = height of dorsal shield of prosoma, PJ xx = serial number of Sparassidae examined by Peter Jager, PL = length of dorsal shield of prosoma, PLE = posterior lateral eyes, PME = posterior median eyes, PP = palpus, PW = width of dorsal shield of prosoma, RTA = retrolateral tibal apophysis, TA = tarsus, TI = tibia, I/II/III/IV = leg I, etc.
Family Sparassidae Bertkau 1872 Genus Heteropoda Latreille 1804 Heteropoda natans new species (Figs. 1-7)
[FIGURES 1-7 OMITTED]
Types.--Male holotype (PJ 1173), female paratype (PJ 1174): Malaysia, Borneo, Sabah, Kinabalu Park, near Poring, Hot Springs, Lowland Rainforest, stream edges, 6[degrees]03'N, 116[degrees]42'E, Airame & Sierwald leg. IV-VI.1998 (FMNH 18975, 18972). Male paratype (PJ 1786): Malaysia, Borneo, Sabah, Kinabalu Park, near Poring Hot Springs. 6[degrees]03'N, 116[degrees]42'E, along river, 600m, Heteropoda male, P. Sierwald det. 1998 (SMF). Female paratype (PJ 1785): same data, Heteropoda female, P. Sierwald det. 1998 (SMF).
Etymology.--The specific name refers to the ability of this species to hunt on the water surface and to dive and hide under water (Latin: natans = swimming), adjective.
Diagnosis.--Tip of conductor divided into two parts as in H. squamacea Wang 1990 from southern China (see Wang 1990: figs. 6, 7), but male dorsal RTA of H. natans with a distinct protrusion between dorsal and ventral part (Fig. 4). Retrolateral margin of conductor undulating. Females with slightly rectangular epigynal field, this with distinct anterior bands. Lateral lobes not touching each other. Median septum anteriorly trapezoid. Spermathecae almost as large as anterior coils of copulatory ducts.
Description.--Male holotype (PJ 1173): PL 10.6, PW 10.2, AW 4.6, PH 2.6, OL 10.5, OW 6.8. Eyes: AME 0.51, ALE 0.71, PME 0.56, PLE 0.71, AME-AME 0.30, AME-ALE 0.08, PME-PME 0.42, PME-PLE 0.66, AMEPME 0.52, ALE-PLE 0.53, CH AME 0.98, CH ALE 0.77. Leg formula: 2143, spination: PP 131,101,2120, FE I-II 323, III 333, IV 331, PA 101, TI I-II 2326, III 2226, IV 2126, MT I-II 1014, III 2014, IV 3036. Leg measurements: PP 17.4 (5.9, 2.6, 3.4, -, 5.5), I 70.8 (18.5, 6.5, 21.1, 19.6, 5.1), II 82.2 (22.0, 6.7, 24.3, 23.7, 5.5), III 62.4 (17.6, 5.9, 18.5, 16.3, 4.1), IV 69.9 (19.6, 5.5, 19.6, 20.5, 4.7).
Chelicerae with 5-6 posterior teeth. Organization of palpal structures simple, i.e. embolus arising in a 6-o'clock-position on the tegulum, following a semi-circular path. Conductor arising in a 9:30-o'clock-position on the tegulum. Sperm duct shaped like broad 'S' across the tegulum.
Color: Reddish-brown to brown with dark markings, made up of short dark hairs. Chelicerae reddish-brown with three longitudinal bands. Prosoma with dark radial markings and a white 'V'-shaped line, consisting of white short hairs, running along the suture between head and thoracical region. Sternum, gnathocoxae, labium, ventral coxae and trochanter pale brown without markings. Opisthosoma covered with dark hairs. Ventral opisthosoma with a light yellowish-brown median band.
Female paratype (PJ 1174): PL 14.9, PW 13.2, AW 6.5, PH 4.1, OL 19.2, OW 12.6. Eyes: AME 0.47, ALE 0.78, PME 0.63, PLE 0.77, AME-AME 0.57, AME-ALE 0.20, PME-PME 0.66, PME-PLE 0.86, AME-PME 0.77, ALE-PLE 0.80, CH AME 1.40, CH ALE 1.12. Leg formula: 2413, spination: PP 131,101,2(1)121,1014(3), FE I-II 323, III 333, IV 331, PA 101, TI I 21(2)26, II-IV 2126, MT I-II 1014, III 2014, IV 3036. Palpal claw with 8 teeth. Leg measurements: PP 22.9 (6.7, 3.2, 5.2, -, 7.8), I 71.9 (20.1, 7.4, 21.2, 18.5, 4.7), II 79.3 (22.7, 7.9, 23.5, 20.2, 5.0), III 65.6 (19.5, 7.1, 18.7, 16.2, 4.1), IV 75.4 (21.1, 7.0, 21.5, 20.7, 5.1).
Chelicerae with = posterior teeth. Lateral lobes of epigyne broad tongue-shaped, covering mainly posterior parts of the median septum. Anterior bands of epigynal field fragmented. Spermathecae separated from each other by one of their diameters. Slit sense organs separated 2.5-4 times of their length from epigynal field (Fig. 5).
Color: As in male, but generally darker (i.e. reddish-brown). Prosoma and opisthosoma covered continously with dark hairs, without any pattern.
Variation.--Male paratype (PJ 1786): PL 11.6, OL 12.1; female paratype (PJ 1785): PL 13.7, OL 12.4.
Distribution.--Only known from the type locality.
Biology.--Observations on the biology of Heteropoda natans were made and published by Airame & Sierwald (2000). Specimens were found sitting at the edge of streams. One specimen was observed jumping into the water and diving. In the laboratory, feeding experiments showed that individuals of H. natans monitor for prey by holding their pedipalps and the first two pairs of legs in the water. From the prey offered to the spiders (cockroaches, fish, large and small tadpoles) only tadpoles were rejected under laboratory conditions. In these experiments cockroaches were the preferred prey.
Heteropoda hosei Pocock 1897 (Figs. 8-10)
[FIGURES 8-10 OMITTED]
Heteropoda hosei Pocock 1897: 614, figs. 21-21a; 1 female syntype (PJ 1765): Malaysia, Sarawak, purchased E. Gerrara, (BMNH 1818.104.22.168-31). Examined and herewith designated as lectotype (see Remarks below).
Diagnosis.--Epigynal field roughly trapezoid with short anterior bands, these neither fragmented nor separated from the field. Median septum covered only on its margins by lateral lobes. Posterior margin of median septum distinctly separated from the epigastric furrow. Spermathecae separated from each other by at least 1.5 times their diameters, extending laterally beyond the first windings of the internal duct system.
Description.--PL 10.0. Slit sense organs separated by their length from the epigynal field (Fig. 8). For further details see Pocock (1897).
Distribution.--Only known from the type locality (Sarawak).
Remarks.--Pocock (1897) mentioned two female specimens in his original description, one from Baram River in Borneo and one from Sarawak. These have to be considered syntypes. In the BMNH only one series of H. hosei was found. It comprises three adult females and one subadult female from Sarawak. One adult female is labelled as type, matches with the original description (the other specimens are smaller and probably added later to the vial) and is considered belonging to the syntype series. The other syntype was not found and its whereabouts remain unkown. To support stability the only located syntype (PJ 1765) is herewith designated as lectotype.
Parts of this research arose from a visit to the BMNH, which was sponsored by the European Community (Access to Research Infrastructure action of the Improving Human Potential Programme: London--SYS-RESOURCE program). Thanks go to Satie Airame and Petra Sierwald (both Chicago) for collecting and providing the specimens and to an anonymous referee and Mark Harvey for improving the manuscript with helpful comments.
Airame, S. & P. Sierwald. 2000. Hunting and feeding behavior of one Heteropoda species in lowland rainforest on Borneo (Araneae, Sparassidae). Journal of Arachnology 28(2):251-253.
Davies, V.T. 1994. The huntsman spiders Heteropoda Latreille and Yiinthi gen. nov. (Araneae: Heteropodidae) in Australia. Memoirs of the Queensland Museum 35(1):75-122.
Jager, P. 2000. Two new heteropodine genera from southern continental Asia (Araneae: Sparassidae). Acta Arachnologica 49(1):61-71.
Jager, P. 2002. Heteropodinae: transfers and synonymies (Arachnida: Araneae: Sparassidae). Acta Arachnologica 51(1):33-61.
Pocock, R.I. 1897. Spinnen (Araneae). In Ergebnisse einer zoologischen Forschungsreise in den Molukken und Borneo. (Kukenthal, W. ed.). Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 33(4):591-629.
Thorell, T. 1890. Diagnoses Aranearum aliquot novarum in Indo-Malesia inventarum. Annali del Museo Civico di Storia Naturale di Genova (2) 10:132-172.
Wang, J.-F. 1990. Six new species of the spiders of the genus Heteropoda from China (Araneae: Heteropodidae). Sichuan Journal of Zoology 9(3):7-11.
Manuscript received 11 February 2004, revised 4 May 2004.
Peter Jager: Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany. E-mail: Peter.Jaeger@Senckenberg.de
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|Publication:||The Journal of Arachnology|
|Date:||Sep 1, 2005|
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