Neoischyrocerus Conlan, 2021, n. comb.
Creators
Description
Genus Neoischyrocerus n. comb.
Supplementary Table S3
Type species. N. claustris J.L. Barnard, 1969
Diagnosis. (with differences from Ischyrocerus in bold). Body length at maturity 1–2 mm (usually), rarely 4–6 mm. Tropical and warm temperate distribution, collected from algae, sponges, corals or from a spiny lobster, 0–16 m, 9– 40°N and 5– 34°S.
Pereon: dorsally smooth (most species), ridged or carinate (some species).
Antenna 1: accessory flagellum 2 articles (second minute), projecting forward or flush with the flagellum; antennae 1 and 2 peduncles subequal in width or antenna 2, 10% wider (based on comparison of antenna 1 peduncle article 2 with antenna 2 peduncle article 4), peduncular setae and setal pattern similar to antenna 1, or slightly shorter, not plumose.
Gnathopod 2, adult male: 190–350% the length of gnathopod 1, basis and propodus especially elongate; coxa 1, 60–110% the depth of coxa 2; basis concave or sinuous; ischium anteriorly rounded; propodus often slender (posterior length 180–400% of central width), palm nearly the full length of the propodus, often with a bulge or tooth defining it proximally at the junction of the carpus (sometimes palm continuous with the carpus), sometimes centrally toothed instead and with shallow bulge or teeth at the junction of the dactyl; dactyl half or nearly the full length of the propodus.
Gnathopod 2, juvenile male: shorter than the adult male gnathopod 2, palm bearing 1–2 strong spines about midway along the length of the propodus, dactyl ending at the spines.
Gnathopod 2, female: only slightly larger than gnathopod 1, palm of the propodus convex (usually) or shallowly concave (rarely).
Pereopods 3 and 4: propodus, posterior margin bearing spines or setae; coxa 4, posterior margin straight, not shallowly concave.
Pereopod 5, male: similar to but shorter than pereopods 6 and 7 or variously modified with posteriorly concave basis or posteriorly expanded and spinose merus.
Uropod 1: peduncle with short ventrodistal spinous process underlying the rami, length ~15–35% of the outer ramus length.
Uropod 3: peduncle bearing 1–2 rows of spines dorsally, ending in a single spine at the distal margin, but without a corona of spines around the margin or setae; rami without spines mid-dorsally, outer ramus subequal to or shorter than the inner and bearing 3–8 minute dorsal cusps apically, without (rarely with) a small apical straight spine.
Component species (with transferred species in bold). Ischyrocerus longimanus (Haswell, 1879) (Australia); I. parvus Stout, 1913 (California); I. carinatus K.H. Barnard, 1916 (South Africa); I. gorgoniae K.H. Barnard, 1940 (South Africa); I. ctenophorus Schellenberg, 1953 (South Africa); Coxischyrocerus inexpectatus (Ruffo, 1959) (Mediterranean, Red Sea?); N. claustris J.L. Barnard, 1969 (California); N. lilipuna J.L. Barnard, 1970 (Hawaii); I. oahu J.L. Barnard, 1970 (Hawaii); I. oahu oahu J.L. Barnard, 1970 (Hawaii); N. chinipa J.L. Barnard, 1979 (Galapagos Islands and Panama); I. oahu armatus Ledoyer, 1979 (Madagascar); Tropischyrocerus socia (Myers, 1989) (Bora Bora); I. mediodens Myers, 1995 (Papua New Guinea); I. parma Myers, 1995 (Papua New Guinea); I. apiensis Myers, 1997 (Samoa); N. vidali Ortiz & Lalana, 2002 (Cuba); C. rhombocoxus Just, 2009 (Australia); T. pugilus Just, 2009 (Australia).
Remarks. Species of Ischyrocerus were transferred to Neoischyrocerus if they demonstrated at least one key character (grossly enlarged and pendulous male gnathopod 2 similar in shape to that of others in the genus; dactyls with comb-like striae as noted in J.L. Barnard (1970), Conlan (1995) and Ortiz & Lalana (2002); similar spination on uropod 3). Presence or absence of these striae were not mentioned by other authors, therefore questioning as to whether this character had been looked for. Mouthpart characteristics were not widely described, but may be useful for generic definition, especially the clavate vs slenderer shape of the mandibular palp and the presence/absence of a long apical seta on the maxilla 1 inner plate.
Excluded but uncertain generic status. Ischyrocerus kapu J.L. Barnard, 1970 from Hawaii. The author based the generic assignment on a single male specimen. He noted its resemblance to N. lilipuna but also considered that it should be in a new genus. On balance, though, he assigned it to Ischyrocerus but noted that this was based on limited information because the specimen lacked antennae and pereopods and the female was also unknown. The male’s gnathopod 2 is unusual in having a long conical extension of the merus underneath the propodus, a feature that is not known for either Ischyrocerus or Neoischyrocerus. Myers (1995) stated that I. kapu is congeneric with other species being transferred to Neoischyrocerus. The male’s propodus is wider than in other members of Neoischyrocerus, but its uropod 3 resembles other species of Neoischyrocerus rather than Ischyrocerus. Further material demonstrating the species’ complete morphology is required before it can be confidently transferred to Neoischyrocerus or to a new genus.
Notes
Files
Files
(27.0 kB)
Name | Size | Download all |
---|---|---|
md5:8c1777a779d967984d06ea8589100dbf
|
27.0 kB | Download |
System files
(33.1 kB)
Name | Size | Download all |
---|---|---|
md5:0541643292e032bb364c58f41198dc88
|
33.1 kB | Download |
Linked records
Additional details
Identifiers
Biodiversity
- Family
- Ischyroceridae
- Genus
- Neoischyrocerus
- Kingdom
- Animalia
- Order
- Amphipoda
- Phylum
- Arthropoda
- Scientific name authorship
- Conlan
- Taxonomic status
- comb. nov.
- Taxon rank
- genus
- Taxonomic concept label
- Neoischyrocerus (Conlan, 2021) sec. Conlan, 2021
References
- Barnard, J. L. (1969) Gammaridean Amphipoda of the rocky intertidal of California: Monterey Bay to La Jolla. Bulletin of the United States National Museum, 258, 1 - 230. https: // doi. org / 10.5479 / si. 03629236.258.1
- Haswell, W. A. (1879) On some additional new genera and species of amphipodous crustaceans. Proceedings of the Linnean Society of New South Wales, 4, 319 - 350. https: // doi. org / 10.5962 / bhl. part. 22854
- Stout, V. R. (1913) Studies in Laguna Amphipoda. Zoologische Jahrbucher. Abteilung fur Systematik, Okologie und Geographie der Tiere, 34, 633 - 659. https: // doi. org / 10.5962 / bhl. part. 19898
- Barnard, K. H. (1916) Contributions to the crustacean fauna of South Africa. 5. The Amphipoda. Annals of the South African Museum, 15 (3), 105 - 302. https: // doi. org / 10.5962 / bhl. title. 10646
- Barnard, K. H. (1940) Contributions to the crustacean fauna of South Africa. 12. Further additions to the Tanaidacea, Isopoda and Amphipoda, together with keys for the identification of hitherto recorded marine and fresh-water species. Annals of the South African Museum, 32, 381 - 543.
- Schellenberg A. (1953) Erganzungen zur Amphipodenfauna Sudwest-Afrikas nebst Bemerkungen uber Brutraumbildung. Mitteilungen aus dem Museum f ʾ r Naturkunde in Berlin. Zoologisches Museum und Institut f ʾ r Spezielle (Berlin), 29 (1), 107 - 126. https: // doi. org / 10.1002 / mmnz. 19530290105
- Ruffo, S. (1959) Contributo alla conoscenza degli anfipodi delle grotte sottomarine. Pubblicazioni della Stazione Zoologica di Napoli, 30 (Supplemento), 402 - 416
- Barnard, J. L. (1970) Sublittoral Gammaridea (Amphipoda) of the Hawaiian Islands. Smithsonian Contributions to Zoology, 34, 1 - 286. https: // doi. org / 10.5479 / si. 00810282.34
- Barnard, J. L. (1979) Littoral gammaridean Amphipoda from the Gulf of California and the Galapagos Islands. Smithsonian Contributions to Zoology, 271, 1 - 149. https: // doi. org / 10.5479 / si. 00810282.271
- Ledoyer, M. (1979) Les gammariens de la pente externe du Grand Recif de Tulear (Madagascar) (Crustacea Amphipoda). Memoir Del Museo Civico Di Storia Naturale Di Verona, IIa Serie, Sezione Scienze Della Vita, 2, 1 - 149.
- Myers, A. A. (1989) Family Ischyroceridae. In: Ruffo, S. (Ed.), The Amphipoda of the Mediterranean. Part 2. Gammaridea (Haustoriidae to Lysianassidae). Memoires de l'Institut oceanographique, Monaco. No. 13. Musee Oceanographique, Monaco, pp. 432 - 438.
- Myers, A. A. (1995) The Amphipoda (Crustacea) of Madang Lagoon: Aoridae, Isaeidae, Ischyroceridae and Neomegamphopidae. Records of the Australian Museum Supplement, 22, 25 - 95. https: // doi. org / 10.3853 / j. 0812 - 7387.22.1995.121
- Myers, A. A. (1997) Amphipoda from the South Pacific: Western Samoa. Records-Australian Museum, 49, 99 - 109. https: // doi. org / 10.3853 / j. 0067 - 1975.49.1997.1260
- Ortiz, M. & Lalana, R. (2002) Primer registro para el Mar Caribe y el Archipielago Cubano del genero Neoischyrocerus (Am- phipoda, Ischyroceridae), con la descripcion de una nueva especie de Cuba. Avicennia, 15, 37 - 42.
- Just, J. (2009) Ischyroceridae. Zootaxa, 2260 (1), 463 - 486. https: // doi. org / 10.11646 / zootaxa. 2260.1.27
- Conlan, K. E. (1995) Thumbing doesn't always make the genus: revision of Microjassa Stebbing (Crustacea: Amphipoda: Ischyroceridae). Bulletin of Marine Science, 57, 333 - 377.