Trischizostoma longirostrum (Freire, Pablo R. & Serejo, Cristiana S. 2004)
| Notice: | This page is derived from the original publication listed below, whose author(s) should always be credited. Further contributors may edit and improve the content of this page and, consequently, need to be credited as well (see page history). Any assessment of factual correctness requires a careful review of the original article as well as of subsequent contributions.
If you are uncertain whether your planned contribution is correct or not, we suggest that you use the associated discussion page instead of editing the page directly. This page should be cited as follows (rationale):
Citation formats to copy and paste
BibTeX: @article{Freire2004Zootaxa645, RIS/ Endnote: TY - JOUR Wikipedia/ Citizendium: <ref name="Freire2004Zootaxa645">{{Citation |
Ordo: Amphipoda
Familia: Lysianassidae
Genus: Trischizostoma
Name
Trischizostoma longirostrum Chevreux, 1919 – Wikispecies link – Pensoft Profile
- Trischizostoma longirostrum Freire, Pablo R., 2004, Zootaxa 645: 5-8.
Materials Examined
Material examined. REVIZEE Program, R/V Thalassa col., stn. E0509, 15 º 47.725 ' S, 038º 21.973 ' W to 15 º 46.378 ' S, 038º 24.839 ' W, 2076m. 12 / 06/ 2000; 1 female, 47 mm, ovigerous, MNRJ15141. Stn. E0528, 19 º 45.258 ' S, 039º 03.003' W to 19 º 47.581 ' S, 038º 59.827 ' W, 1237m, 29 /06/2000, 1 female with oostegites, 25 mm, MNRJ15142. Stn. E 0 535, 19º 58.936 ' S, 039º 38.657 ' W to 19 º 56.087 ' S, 039º 35.408 ' W, 1002 m, 01/07/2000, 1 female with oostegites, 39 mm, MNRJ15143. Type locality. Northeast Atlantic, between Dakar and Cabo Verde Islands. Diagnosis. Eyes present. Maxilliped palp with 4 articles and longer than outer plate. Gnathopod 1 propodus oval and anteriorly excavate. Gnathopod 2, coxa with anterior margin rounded; ischium subequal to carpus in length. Pereopod 3 basis 2 X length of propodus. Telson entire, distally truncate.
Description
Description. Female, 39 mm (Fig. 3 A). Rostrum reaching middle of first article of antenna 1 peduncle. Eyes well developed. Antenna 1, first article of peduncle longer than articles 2–3 and shorter than callynophore. Antenna 2, peduncle article 4 subequal in length and broader than article 5. Mandibles with small distal incisor; palp 3 articulate and bearing marginal setae. Maxilla 1, inner plate 1 / 3 length of outer plate, with 8 distal setae, palp reduced and attached on median part of outer plate. Maxilla 2, inner and outer plates subequal in length; outer plate with 4 lateral setae. Maxilliped, inner plate shorter than outer plate; palp with 4 articles and longer than outer plate. Gnathopod 1 (Fig. 3 B), strongly subchelate; coxa reduced and partially covered by coxa 2; propodus inverted, oval, anteriorly excavated; palm with stout setae in all its extension and 3 pairs of longer setae distally. Gnathopod 2 (Fig. 3 C), coxa with anterior margin rounded; ischium shorter than basis and subequal to carpus; propodus less than halflength of carpus; dactylus reduced. Pereopod 3 (Fig. 3 D), coxa longer than broad; basis 2 X length of propodus; carpus slightly longer than propodus; dactylus less than halflength of propodus; carpus, propodus and dactylus covered with minute and stout setae on posterior margin. Pereopod 4, coxa posteriorly excavated; basis longer than carpus and merus together; propodus as long as carpus; dactylus less than halflength of propodus. Coxae 5–7 broader than long. Basis of pereopods 5–7 longer than broad and with posterior lobe. Pereopods 5 and 7, carpus as long as merus, and longer than propodus. Pereopod 6, carpus as long as propodus and slightly shorter than merus. Uropods 1 and 2, peduncle subequal to outer ramus; inner ramus slightly longer than outer ramus. Uropod 3, peduncle less than half of outer ramus; inner and outer rami subequal in length; outer ramus 2 articulate, with a basal article 5 X length of distal article. Telson entire, truncate (Fig. 3 E).
Distribution
Distribution. North Atlantic and Southwest Atlantic, off Brazilian coast (15 º to 19 º S).
Discussion
Remarks.Trischizostoma longirostrum is part of the group of species with maxilliped palp longer than outer plate, anterior margin of coxa 2 rounded, and telson entire, which includes: T. richeri Lowry & Stoddart 1994, T. nicaeense Costa 1853, T. macrochela Vinogradov 1990, and T. circulare. Among these species, T. longirostrum is very close to T. richeri in the oval shape of propodus of gnathopod 1. The distinctions between them are on carpus of gnathopod 2, which is subequal to ischium in T. longirostrum and longer than ischium in T. richeri; basis of pereopod 3, which is twice the length of propodus in T. longirostrum and 3 X the length of propodus in T. richeri; the anterior margin of propodus of gnathopod 1, which is excavated in T. longirostrum; and the telson shape, which is distally truncate in T. longirostrum and distally acute in T. richeri. Chevreux (1927) used the length of rostrum as a diagnostic character. However, this character is variable in different stages of the individual within this genus. Examining juvenile specimens of T. raschi and T. denticulatum showed that the rostrum is relatively longer when compared with adults forms. A curiosity observed was the absence of eyes in the largest individual (47 mm) found within our samples. Smaller specimens (25 mm and 39 mm) had weak eyes. Modification on the ending of the specific name is proposed. The name Trischizostoma (from the Greek stoma, mouth) has a neuter gender that needs to be followed by the correct adjective declination um (Brown, 1956).
Taxon Treatment
- Freire, Pablo R.; Serejo, Cristiana S.; 2004: The genus Trischizostoma (Crustacea: Amphipoda: Trischizostomidae) from the Southwest Atlantic, collected by the REVIZEE Program, Zootaxa 645: 5-8. doi
This treatment was originally uploaded by Plazi, compare this treatment on Plazi. Unless this treatment has been substantially changed on Species-ID, Plazi requests to maintain a link back to the original repository.
