Family HADZIIDAE S. Karaman, 1943

Liagoceradocus subthalassicus

© Copyright from Bradbury & Williams 1996: fig. 1.

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Introduction

As Lowry & Hughes (2009) pointed out, now that the Maeridae Krapp-Schickel, 2008a is recognised as distinct from the Melitidae Bousfield, 1973, it becomes apparent how morphologically similar the genera of Maeridae are to those of the freshwater family Hadziidae S. Karman, 1943. Although hadziids generally have differently shaped gnathopods, third uropods and telsons from maerids, the only character we can currently find to separate the two families definitively, is the stalked gills (with partial or complete proximal diaresis) of the Hadziidae. Maerids are mostly marine and hadziids are mostly freshwater. Generally, hadziids occur in habitats such as marine interstitial, anchialine, and subterranean freshwaters that were once connected to the sea. In Australia, these habitats are occupied mainly by crangonyctoid and melitid amphipods. Two hadziid genera are known from tropical Australia: the widespread genera, Hadzia S. Karaman, 1932 and Dulzura J.L. Barnard, 1969.

Diagnosis

Head as long as deep or longer than deep; anteroventral margin weakly recessed, rounded, straight or oblique and shallowly excavate or not; anteroventral corner rounded, subquadrate or absent; rostrum absent; eyes absent. Body laterally compressed or subcylindrical; smooth; with sparse slender setae or with sparse slender or robust dorsal setae on urosome or without setae. Antenna 1 longer than antenna 2; peduncular article 1 subequal to, or longer than article 2; article 2 longer than article 3; article 3 shorter than article 1; accessory flagellum present or absent; primary flagellum 5- or more articulate; callynophore absent. Antenna 2 short; flagellum shorter than peduncle; less than 5-articulate. Mandible incisor dentate; lacinia mobilis present on both sides; molar fully triturating. Maxilla 1 inner plate strongly setose along medial margin. Maxilliped inner plates well developed; outer plates large or small. Coxae 1–4 longer than broad or broader than long, overlapping. Gnathopod 1 not sexually dimorphic; smaller (or weaker) than gnathopod 2; subchelate; coxa subequal to coxa 2; carpus subequal to, or longer than propodus; propodus palm with or without peg-like robust setae along margin. Gnathopod 2 sexually dimorphic; subchelate; coxa subequal to but not hidden by coxa 3; ischium short; carpus short, shorter than propodus, slightly or not produced along posterior margin of propodus. Pereopod 3 coxa longer than broad or expanded distally; carpus subequal to propodus, not produced. Pereopod 4 coxa subequal to, or larger than coxa 3, with well-developed posteroventral lobe; carpus subequal to propodus, not produced. Pereopod 5 shorter than pereopod 6; coxa smaller than coxa 4, with posterodorsal lobe; basis expanded or slightly expanded, with posteroventral lobe; carpus linear, dactylus with or without setae along margin or with a few subterminal setae. Pereopod 6 subequal to pereopod 7; basis expanded; dactylus with or without setae along margin or with a few subterminal setae. Pereopod 7 longer than pereopod 5; basis expanded. Pleonites 1–3 with or without transverse dorsal serrations; with slender or without slender or robust dorsal setae. Urosomite 1 longer than urosomite 2. Uropods 1–3 similar in structure and size or radically dissimilar. Uropods 1–2 apices of rami with robust setae. Uropod 1 peduncle with 1 or 2 basofacial robust setae. Uropod 3 biramous; peduncle short; rami lanceolate or foliaceous; outer ramus longer than peduncle; inner ramus not apically setose. Telson laminar; deeply cleft; longer than broad or as long as broad; dorsal robust setae present; apical robust setae present.

General References

Barnard, J.L. 1969. The families and genera of marine gammaridean Amphipoda. Bulletin of the United States National Museum 271: 1-535

Barnard, J.L. & Barnard, C.M. 1983. Freshwater Amphipoda of the World. I. Evolutionary Patterns. II. Handbook and Bibliography. Virginia : Hayfield Associates 830 pp.

Bousfield, E.L. 1979. A revised classification and phylogeny of amphipod crustaceans. Transactions of the Royal Society of Canada 16: 343-390

Bousfield, E.L. 1983. An updated phyletic classification and paleohistory of the Amphipoda. pp. 257-276 in Schram, F.R. (ed.). Crustacean Phylogeny. Rotterdam : A.A. Balkema.

Bradbury, J.H. & Williams, W.D. 1996. Two new species of anchialine amphipods (Crustacea, Hadziidae, Liagoceradocus) from Barrow Island, Western Australia. Records of the Western Australian Museum 17(4): 395-409

Holsinger, J.R. 1994. Amphipoda. pp. 147-163 in Juberthie, C. & Decou, V. (eds). Encyclopaedia Biospeologica. Moulis & Bucarest : Société de Biospéologie Vol. 1.

Karaman, S. 1943. Die unterirdischen Amphipoden Südserbiens. Srpska Akademya Nauka, Posebna Izdana 135 (Prirodn'achki i Matematichki Spici) 34(4): 161-312

Lowry, J.K. & Hughes, L.E. 2009. Maeridae, the Elasmopus group. pp. 643-702 in Lowry, J.K. & Myers, A.A. (eds). Benthic Amphipoda (Crustacea: Peracarida) of the Great Barrier Reef, Australia. Zootaxa 2260: 1-930

Stock, J.H. 1986. Amphipoda: Melitid grouping (Melitidae sensu Bousfield, 1973, emend.). pp. 504-513 in Botosaneanu, L. & Stock, J.H. (eds). Stygofauna Mundi. A Faunistic, Distributional, and Ecological Synthesis of the World Fauna Inhabiting Subterranean Waters (including the Marine Intersitial). Leiden : E.J. Brill & Dr. W. Backhuys.

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