Family ISCHYROCERIDAE Stebbing, 1899

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Introduction

Myers & Lowry (2003) revised the Ischyroceridae and established a subfamily and tribe structure within the group. In Australia and the Australian Antarctic Territories (particularly Macquarie Island) the ischyrocerin and siphonoecetin tribes are both well represented. Within the Siphonoecetini, Just (1988) showed the phylogenetic relationships between genera in the Siphonoecetes group and Lowry & Berents (1996) did the same for the Cerapus group. A key to ischyrocerid genera is imbedded in the corophiid key of Barnard & Karaman (1991), but there is a separate key to siphonoecetids.

Ischyrocerids are cosmopolitan and are nestlers in algae, or tube-dwellers among algae or on hard or sandy substrates (Lowry 1981; Just 1984, 1988; Conlan 1990; Lowry & Berents 2003). They can at times be among the dominant algal-dwelling amphipods (Fenwick 1976; Edgar 1983), but there is no evidence to indicate that they are herbivores. Vader & Myers (1996) documented for the first time species of ischyrocerids living as associates of hermit crabs. They described two new genera and and four new species, two in the genus Ventojassa, living in association with the hermit crabs Dardanus arrosor and Trizopagurus strigimanus. Recently, Lowry and Berents (2005) described three new species; Hughes and Lowry (2006) two new species; and Just (2009) described five new species.

Currently, 231 ischyrocerid species are recognised. Forty-six species are recorded from Australia.

 

Diagnosis

Head as long as deep, longer than deep or deeper than long; anteroventral margin moderately or strongly recessed and deeply or shallowly excavate; rostrum short, moderate, long or absent; eyes well developed (round or ovoid), obsolescent or absent. Body cylindrical, subcylindrical or laterally compressed; smooth. Antenna 1 shorter than, subequal to, or longer than antenna 2; peduncular article 1 shorter than, subequal to, or longer than article 2; article 2 shorter than, subequal to, or longer than article 3; article 3 shorter than, subequal to, or longer than article 1; accessory flagellum present or absent; primary flagellum less than or more than 5-articulate; callynophore absent. Antenna 2 short, medium length or long; flagellum shorter than, as long as or longer than peduncle; less than or more than 5-articulate. Mandible incisor dentate; lacinia mobilis present on both sides; molar fully triturating. Maxilla 1 inner plate weakly setose apically or without setae. Maxilliped inner plates well developed; outer plates large or small. Coxae 1–4 longer than broad, as long as broad or broader than long, overlapping or discontiguous; coxae 1–3 with none vestigial or reduced or with coxa 1 vestigial or reduced. Gnathopod 1 sexually dimorphic or not; smaller (or weaker) than, subequal to, or larger (or stouter) than gnathopod 2; simple or subchelate; coxa vestigial, hidden or partially hidden by coxa 2 or smaller than or subequal to coxa 2; carpus shorter than, subequal to, or longer than propodus. Gnathopod 2 sexually dimorphic or not; simple, carpochelate or subchelate; coxa smaller than or subequal to but not hidden by coxa 3; ischium short; carpus short or long, shorter than, subequal to, or longer than propodus. Pereopods heteropodous (3–4 directed posteriorly, 5–7 directed anteriorly) or homopodous (3–7 directed posteriorly); 3–4 with or without glandular basis. Pereopod 3 coxa longer than broad or as long as broad; carpus shorter or longer than propodus, produced anteriorly or not. Pereopod 4 coxa subequal to coxa 3, acuminate ventrally or not, with or without well developed posteroventral lobe; carpus shorter than or subequal to propodus, not produced. Pereopod 5 shorter than or subequal to pereopod 6; coxa smaller than, subequal to, or larger than coxa 4, with or without posterodorsal lobe; basis expanded or slightly expanded, subrectangular, without posteroventral lobe; carpus linear or reniform; dactylus well developed or minute. Pereopod 6 shorter than or subequal to pereopod 7; basis expanded, slightly expanded or linear. Pereopod 7 longer than pereopod 5; similar or different in structure to pereopod 6; basis with broad posteroventral lobe, subrectangular or subovate, with or without dense long slender setae. Pleonites 1–3 with or without lateral ridging. Epimeron 2 setose or without setae. Urosome dorsoventrally flattened or not; urosomites 1–3 free or 1 and 2 free, 3 coalesced with telson or 1 and 2 coalesced, 3 coalesced dorsally with telson; urosomite 1 longer than urosomite 2. Uropods 1–3 similar in structure and size or radically dissimilar. Uropods 1–2 apices of rami with or without robust setae. Uropod 1 peduncle with or without ventromedial spur. Uropod 3 biramous, uniramous or rami absent; peduncle long; rami lanceolate or vestigial; outer ramus shorter than or subequal to peduncle, with or without recurved spines; inner ramus not apically setose. Telson thickened dorsoventrally; deeply, moderately or weakly cleft or entire; longer than broad, as long as broad or broader than long; dorsal robust setae present or absent; apical robust setae absent.

 

General References

Barnard, J.L. & Karaman, G.S. 1991. The families and genera of marine gammaridean Amphipoda (except marine gammaroids). Records of the Australian Museum, Supplement 13: 1-866

Conlan, K.E. 1990. Revision of the crustacean amphipod genus Jassa Leach (Corophioidea: Ischyroceridae). Canadian Journal of Zoology 68: 2031-2075

Edgar, G.J. 1983. The ecology of south-eastern Tasmanian phytal animal communities. I. Spatial organisation on a local scale. Journal of Experimental Marine Biology and Ecology 70: 129-157

Fenwick, G.D. 1976. The effect of wave exposure on the amphipod fauna of the alga Caulerpa brownii. Journal of Experimental Marine Biology and Ecology 25: 1-18

Hughes L.E. & Lowry J.K. 2006. New species of Amphipoda (Crustacea: Peracarida) from the Solitary Islands, New South Wales, Australia. Zootaxa 1222: 1-52

Just, J. 1983. Siphonoecetinae subfam. n. (Crustacea, Amphipoda, Corophiidae) 1: Classification. Steenstrupia 9(6): 117-135

Just, J. 1984. Siphonoecetinae (Crustacea, Amphipoda, Corophiidae) 2: Caribboecetes Just, 1983, with description of six new species. Steenstrupia 10(2): 37-64

Just, J. 1988. Siphonoecetinae (Corophiidae) 6: a survey of phylogeny, distribution, and biology. Crustaceana Suppl. 13: 193-208

Just, J. 2009. Ischyroceridae. pp. 463-486 in Lowry, J.K. & Myers, A.A. (eds). Benthic Amphipoda (Crustacea: Peracarida) of the Great Barrier Reef, Australia. Zootaxa 2260: 1-930

Lowry, J.K. 1981. The amphipod genus Cerapus in New Zealand and Subantarctic waters (Corophioidea, Ischyroceridae). Journal of Natural History 15: 183-211

Lowry, J.K. & Berents, P.B. 1996. The Ericthonius group, a new perspective on an old problem (Crustacea: Amphipoda: Corophoidea). Records of the Australian Museum 48: 75-109

Lowry, J.K. & Berents, P.B. 2003. Algal-tube dwelling amphipods in the genus Cerapus from Australia and Papua New Guinea (Crustacea: Amphipoda: Ischyroceridae). Records of the Australian Museum 57: 153-164

Myers, A.A. & Lowry, J.K. 2003. A phylogeny and a new classification of the Corophiidea Leach, 1814 (Amphipoda). Journal of Crustacean Biology 23(2): 443-485

Stebbing, T.R.R. 1899. Revision of Amphipoda (continued). Annals and Magazine of Natural History 7 4: 205-211

Vader, W. & Myers, A.A. 1996. Amphipods living in association with hermit crabs in SE Australia. Four new Ischyroceridae. Bollettino del Museo Civico di Storia Naturale di Verona 20: 263-292 [Date published 31 Oct 1996]

 

History of changes

Published	As part of group	Action Date	Action Type	Compiler(s)
05-Aug-2022	AMPHIPODA	12-Feb-2013	MOVED	Dr Jim Lowry (AM)
05-Aug-2022		06-Feb-2013	MODIFIED
05-Aug-2022		22-Nov-2012	MODIFIED
05-Aug-2022		19-Dec-2011	MODIFIED
05-Aug-2022		02-Jul-2010	MODIFIED
		12-Feb-2010	(import)