Natatolana californiensis ( Schultz, 1966 )

Keable, Stephen J., 2006, Taxonomic Revision of Natatolana (Crustacea: Isopoda: Cirolanidae), Records of the Australian Museum 58 (2), pp. 133-244 : 164-165

Natatolana californiensis ( Schultz, 1966)

Cirolana californiensis Schultz, 1966: 14 , pl. 8.–1969: 178, fig. 276.–Brusca & Ninos, 1978: 379, figs. 1–7.

Cirolana deminuta Menzies & George, 1972: 19 , figs. 12–13.– Brusca & Ninos, 1978: 379.– Bruce, 1986: 218.

Natatolana californiensis .– Bruce, 1981: 958.– 1986: 218, 222.– Brusca & Iverson, 1985: 37, fig. 11E.– Brusca et al., 1995: 84, figs. 65A, 66, 67.–Espinosa-Pérez & Hendrickx, 2001: 48.

Type material of N. californiensis . Holotype: male (not female as originally recorded), 8.0 mm, LACM 60.88.4, AHF Type No. 6048 ( Brusca et al., 1995). Paratypes: 2 (apparently 1 lost as Schultz (1966) indicated 3 specimens in addition to the holotype), LACM 60.76.3, AHF Cat. No. 952-1 San Clemente Island, Tanner Canyon, 54.8 km. 250°T from China Point Light, Channel Islands, Los Angeles County, California, USA, 32°37.87'N 118° 58.70'W, 792 m, RV Velero IV, Sta. 6833-60, 29 Jan. 1960 ( Wetzer et al., 1991; Brusca et al., 1995). None examined. Type locality of N. californiensis: Coronado Canyon , southern California, USA. Originally cited as 32°37'54"N 118°55'40"W, 812 m, [Velero IV station 6851] but emended to 32°30.70'N 117°21.62'W, 8.6 km, 322.5°T from North Coronado Island, San Diego County, on green mud, 794 m, [Velero IV Sta. 6851-60, 1 Feb. 1960] (Wetzer et al.; Brusca et al., 1995).

Type material of N. deminuta . Holotype: ♀, 17 mm, USNM 121749 (examined). Type locality of N. deminuta: Peru-Chile Trench , 7°58'S 80°37'W, 1005–1124 m, [ Anton Bruun Station 88].

Material examined. USA: 33, USNM 113588 , SW of San Clemente Island, California, 32°41.6'N 118°41'W, Hagfish trap, Hubbs, Newman et al., 26–27 Sep. 1965, Agassiz stn MV 65.III.35 .

Diagnosis. Eyes: absent or vestigial (there can be a small patch indicating vestigial ommatidia). Interocular furrow: moderately developed, distinct but not extending across the cephalon; smoothly convex. Frontal lamina: lateral margins straight, narrowing anteriorly. Antenna: c. 0.45× as long as body, reaching to approximately half way along pereonite 4. Coxal plates: furrows moderately developed on coxae 2–4 and strongly developed on coxae 5–7. Pleonite 4: apex forming a broad acute point or rounded (mostly produced into a broad acute point but in a few specimens it is worn into a rounded shape). Pleotelson: broad, length 0.77–0.88× basal width; anterodorsal depression absent (but with shallow paired submedian depressions near base that do not form a distinct and abrupt depression as in species such as N. pellucida ); anterolateral margins convex; posterolateral margins convex; apex not produced, lateral margins converging smoothly to a point; with 6–10 RS. Pereopod 2: propodus with 1–3 RS on palm. Pereopod 3: propodus with 1–3 RS on palm. Pereopods 5–7: propodus long, on pereopod 5 greatly elongate, 2× that of pereopod 7. Pereopod 7: basis narrow, width 0.35–0.47× length; distance between anterior margin and medial carina less than between posterior margin and medial carina; posterior margin with setae along entire length ( Brusca et al. (1995) do not show setae on this margin. Their illustration, however, is a lateral view (no medial carina shown). In the material examined here, the short slender setae occurring along the length of this margin are difficult to see and would not be apparent in a lateral view). Penes: present. Pleopod 2 appendix masculina: extending beyond tip of endopod, 1.09× length of endopod; margins very strongly curved laterally; slender; apex not at angle to adjacent margins, bluntly rounded. Uropods: exopod slightly shorter than endopod, 0.86× the length of the endopod.

Variation. Brusca & Ninos (1978) recorded a range of 10– 21 articles for the antennal flagellum, Brusca et al. (1995) give a range of 10–22. In the smallest subadult examined here there is at least 17 articles. Possibly the figure of 10 articles was based on the illustration of C. deminuta by Menzies & George (1972), which is erroneous.

Size. Adults to 13.4 mm.

Remarks. Schultz (1966) did not illustrate an interocular furrow for Natatolana californiensis . In the material examined, however, a distinct, incomplete interocular furrow is apparent. Brusca & Ninos (1978) synonymized N. deminuta with N. californiensis . The holotype of N. deminuta has the apex of the pleotelson more produced than that described for N. californiensis and appears to have had 12–14 robust setae on the pleotelson, many of which have been broken off. Brusca & Ninos (1978) recorded the range of robust setae on the pleotelson of N. californiensis as six to 12 but this was modified by Brusca et al. (1995) as six to 10. The illustration of Brusca et al. (1995) shows eight robust setae on the pleotelson margins of the holotype of N. californiensis . Of the material examined here, the most common number of robust setae on the pleotelson is eight although some specimens have nine. The material of N. californiensis examined here and the holotype of N. deminuta both have a broad acute posterolateral margin on pleonite 4. It is, however, somewhat narrower and less rounded in the holotype of N. deminuta . The holotype of N. californiensis lacks setae on the endopod of pleopod 5 ( Brusca et al., 1995), but these are present on the holotype of N. deminuta (pers. obsv.). Given these differences, and the distance between the type locality of N. deminuta and records of N. californiensis , they may not be synonyms. The holotype of N. deminuta , however, is in poor condition and, because it is a female, diagnostic characters, such as the shape of the appendix masculina or presence of penes, cannot be assessed. Therefore, further material from the proximity of the type locality of N. deminuta is needed to resolve the question of whether it represents a valid species of Natatolana or a synonym of N. californiensis .

Distribution and ecology. Natatolana californiensis has been recorded from the west coast of North, Central and South America. The species has mostly been recorded from southern California and Mexico, with a single record from Costa-Rica ( Brusca et al., 1995; Espinosa-Pérez & Hendrickx, 2001). The holotype of Natatolana deminuta that Brusca & Ninos (1978) synonymized with N. californiensis was collected from the Peru-Chile Trench. Brusca & Ninos (1978) indicated that most specimens are collected at depths of 700–2000 m, although a few specimens have been collected from depths as shallow as 40 m and 250 m. Alternatively, Brusca et al. (1995) cite the distribution as including depths of 792–1250 m. Scavenger (some of the material examined in this study was from a hag fish trap and was therefore presumably scavenging on bait or the catch in the trap).