Research Article |
Corresponding author: Stephen C. Landers ( slanders@troy.edu ) Academic editor: Pavel Stoev
© 2016 Stephen C. Landers, Martin V. Sørensen.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Landers SC, Sørensen MV (2016) Two new species of Echinoderes (Kinorhyncha, Cyclorhagida), E. romanoi sp. n. and E. joyceae sp. n., from the Gulf of Mexico. ZooKeys 594: 51-71. https://doi.org/10.3897/zookeys.594.8623
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Meiofauna sampling on the continental shelf of the northern Gulf of Mexico has been ongoing since 2007, on annual cruises in collaboration with the National Marine Fisheries Service laboratory in Pascagoula, Mississippi. This sampling has resulted in numerous new species of kinorhynchs from the shelf sediment, two of which are described in detail in this paper. Other species descriptions from this research effort include Echinoderes augustae, E. skipperae, and E. charlotteae. We now describe Echinoderes romanoi sp. n. and E. joyceae sp. n., which are unique in their spine, tube, and glandular cell outlet patterns.
Echinoderidae , kinorhynchs, meiofauna, morphology, taxonomy
Diversity in the phylum Kinorhyncha has been underreported from the Gulf of Mexico, though recently new investigations are adding to our knowledge of the Gulf species. Currently there are few kinorhynchs identified to species from the Gulf, though their presence and abundance are well documented. The known species diversity in the Gulf of Mexico includes Echinoderes steineri (Chitwood, 1951), E. coulli
Sediment was collected along the northern Gulf of Mexico continental shelf during several NOAA cruises from 2010 to 2015 in collaboration with the NMFS lab in Pascagoula, Mississippi, on NOAA ships Gordon Gunter, Pisces, and Oregon II. Sediment was collected in 2010–2012 using a Shipek® sediment grab, and in 2013–2015 using an Ocean Instruments® mini-multicorer. Specimens from the present study were obtained from 12 locations located along the northern Gulf of Mexico continental shelf (Fig.
Summary of data on stations, species identities and catalogue numbers (KIN-) for specimens deposited at the Natural History Museum of Denmark.
Station | Date | Position | Depth, |
---|---|---|---|
Salinity (ppt) | Species | Mounting | Type status and catalogue numbers |
149-2010 | Nov. 21, 2010 | 28° 31'9"N | |
86° 18'54"W (28.5192°, -86.3151°) | 443 m | ||
35.2 | Echinoderes romanoi sp. n. | LM | 1 ♂ nontype |
154-2010 | Nov. 22, 2010 | 29° 22'28"N | |
86° 41'46"W (29.3747°, -86.6962°) | 382 m | ||
35.4 | Echinoderes romanoi sp. n. | LM | 1 ♂ paratype, KIN-967, 1 ♂ and 1♀ non-types |
050-2013 | Nov. 2, 2013 | 28° 14'21.12"N | |
90° 52'1.91"W | |||
(28.2392°, -90.8672°) | 74 m | ||
36.5 | Echinoderes romanoi sp. n. | LM | 1 ♂ paratype, KIN-899 |
012-2014 | Nov. 13, 2014 | 29° 15'10"N | |
88° 18'23"W (29.2528°, -88.3066°) | 90 m | ||
36.3 | Echinoderes romanoi sp. n. | SEM | |
LM | 1 ♂ nontype | ||
1 ♂ holotype, KIN-962, 2 ♀ paratypes, KIN-963 to KIN-964 | |||
019-2014 | Nov. 14, 2014 | 28° 43'52"N | |
89° 34'16"W (28.7313°, -89.5712°) | 94 m | ||
36.3 | Echinoderes romanoi sp. n. | LM | 2 ♀ paratypes, KIN-965 to KIN-966 |
1 ♂ nontype | |||
026-2014 | Nov. 16, 2014 | 28° 27 25"N | |
91° 31 53"W (28.4572°, -91.5314°) | 52 m | ||
36.2 | Echinoderes romanoi sp. n. | SEM | |
LM | 1 ♀ non type | ||
1 ♀ non type | |||
130-2015 | Nov. 4, 2015 | 28° 32'45"N | |
91° 53'21"W | |||
(28.5459 °, -91.8894°) | 45 m | ||
36.0 | Echinoderes romanoi sp. n. | SEM | 1 ♀ non type |
010-2010 | Oct. 16, 2010 | 27°09'12"N | |
96°09'59"W | |||
(27.1534°,-96.1666°) | 427 m | ||
35.2 | Echinoderes joyceae sp. n. | LM | 1 ♂ holotype KIN-845, |
1 ♀ paratype KIN-849 | |||
016-2010 | Oct. 17, 2010 | 27°47'58"N | |
95°38'11"W | |||
(27.7995°, -95.8345°) | 57 m | ||
36.4 | Echinoderes joyceae sp. n | LM | 1 ♂ paratype KIN-850 |
068-2012 | Oct. 22, 2012 | 28°05'12"N | |
91°38'59"W | |||
(28.0868°, -91.6365°) | 99 m | ||
36.4 | Echinoderes joyceae sp. n | LM | 1 ♂ paratype KIN-922 |
031-2013 | Oct. 30, 2013 | 28°01'55"N | |
93°13'29"W | |||
(28.0320°, -93.2249°) | 99 m | ||
31.2 | Echinoderes joyceae sp. n | LM | 1 ♂ paratype KIN-867 |
033-2014 | Oct. 20, 2014 | 29° 32'32"N | |
86 °11'33"W | |||
(29.5423°, -86.1926°) | 98 m | ||
35.3 | Echinoderes joyceae sp. n | SEM | 1 ♀ nontype |
The samples were fixed immediately in 5–10% formalin on the cruise, and the meiofauna was subsequently extracted by Ludox centrifugation (
Specimens for scanning electron microscopy were observed at the Auburn University Research Instrumentation Facility (Auburn, Alabama). Specimens stored in 70% isopropanol were hydrated, post-fixed in OsO4 vapor, then dehydrated to 100% ethanol through a graded series, critical point dried, mounted on aluminum stubs, and sputter-coated with gold. Specimens were photographed with a Zeiss EVO 50 SEM, using the backscatter and secondary electron detectors.
Holotype: Adult male (
Echinoderes with middorsal spines on segments 4–8, and spines in lateroventral positions on segments 6–9. Tubes present in lateroventral position on segment 5. Glandular cell outlets type 2 present in subdorsal, laterodorsal, sublateral, and ventrolateral positions on segment 2, in midlateral position on segment 5, and in sublateral position on segment 8.
Adults with head, neck and eleven trunk segments, ranging from 196–247 µm in trunk length (Figs
Line art illustrations of Echinoderes romanoi sp. n. A Male, dorsal view B Male, ventral view C Female, segments 10 to 11, dorsal view D Female, segments 10 to 11, ventral view. Abbreviations: gco1/2, glandular cell outlet type 1/2; ld, laterodorsal sensory spot; ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral spine; lvt, lateroventral tube; ml, midlateral sensory spot; pa, pachycyclus; pd, paradorsal sensory spot; pe, penile spine; pv, paraventral sensory spot; sd, subdorsal sensory spot; si, sieve plate; sl, sublateral sensory spot; vm, ventromedial sensory spot.
Light micrographs showing overviews and details in male holotype
Scanning electron micrographs showing overviews and details in head and trunk morphology of Echinoderes romanoi sp. n. A Right lateroventral view of anterior end of a female B Oral stylets and introvert C Right lateral overview of a male D Right lateral view of segments 8 to 11 of a male E Trunk segments 5 to 8, lateral view F Segments 9 to 11 of a female, ventral view. Abbreviations: gco2, glandular cell outlet type 2; go, gonopore; ld, laterodorsal sensory spot; ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral spine; lvt, lateroventral tube; mds, middorsal spine; ml, midlateral sensory spot; pd, paradorsal sensory spot; pe, penile spine; psp, primary spinoscalid; sd, subdorsal sensory spot; sp2–3, spinoscalids of Rings 2 to 3; spf, secondary pectinate fringe; vl, ventrolateral sensory spot; vm, ventromedial sensory spot.
Measurements from light microscopy of Echinoderes romanoi sp. n. (in µm) from the Gulf of Mexico, including number of measured specimens (n) and standard deviation (SD). Abbreviations: (ac): acicular spine; LTAS: lateral terminal accessory spine; LTS: lateral terminal spine; LV: lateroventral; MD, middorsal; MSW-7: maximum sternal width, measured on segment 7 in this species; S: segment lengths; SW-10, standard width, always measured on segment 10; TL: trunk length.
Character | n | Range | Mean | SD |
---|---|---|---|---|
TL | 10 | 196–247 | 227 | 15.08 |
MSW-7 | 10 | 37–44 | 39 | 2.28 |
MSW-7/TL | 10 | 15–20.8% | 17.3% | 1.87% |
SW-10 | 10 | 30–35 | 33 | 1.58 |
SW-10/TL | 10 | 13–16.5% | 14.4% | 1.15% |
S1 | 10 | 20–24 | 22 | 1.33 |
S2 | 10 | 20–24 | 22 | 1.45 |
S3 | 10 | 21–26 | 24 | 1.51 |
S4 | 10 | 21–27 | 24 | 1.75 |
S5 | 10 | 24–29 | 26 | 1.64 |
S6 | 10 | 25–30 | 28 | 1.51 |
S7 | 10 | 27–32 | 30 | 1.57 |
S8 | 10 | 27–33 | 31 | 1.77 |
S9 | 10 | 29–34 | 32 | 1.58 |
S10 | 10 | 28–33 | 30 | 1.83 |
S11 | 10 | 22–30 | 25 | 2.42 |
MD4 (ac) | 10 | 23–49 | 30 | 7.23 |
MD5 (ac) | 8 | 24–55 | 39 | 10.04 |
MD6 (ac) | 9 | 34–65 | 46 | 9.30 |
MD7 (ac) | 10 | 36–68 | 50 | 9.54 |
MD8 (ac) | 10 | 48–73 | 62 | 8.15 |
LV6 (ac) | 10 | 19–35 | 25 | 5.57 |
LV7 (ac) | 10 | 19–36 | 27 | 6.00 |
LV8 (ac) | 10 | 18–42 | 27 | 6.81 |
LV9 (ac) | 8 | 19–46 | 28 | 7.87 |
LTS | 10 | 127–232 | 154 | 32.18 |
LTS/TL | 10 | 55.8–109.4% | 68.4% | 16.91% |
LTAS | 5 | 45–77 | 62 | 13.38 |
Summary of nature and location of sensory spots, glandular cell outlets, tubes and spines arranged by series in Echinoderes romanoi sp. n. Abbreviations: LA: lateral accessory; LD: Laterodorsal; LV: lateroventral; MD: middorsal; ML: midlateral; PD: paradorsal; PV: paraventral; SD: subdorsal; SL: sublateral; VL: ventrolateral; VM: ventromedial; ac, acicular spine; gco 1/2, glandular cell outlet type 1/2; ltas, lateral terminal accessory spine; lts, lateral terminal spine; pe, penile spines; si, sieve plate; ss, sensory spot; tu, tube; (♀), female and (♂), male conditions of sexually dimorphic characters.
Position Segment |
MD | PD | SD | LD | ML | SL | LA | LV | VL | VM | PV |
---|---|---|---|---|---|---|---|---|---|---|---|
1 | gco1 | ss | ss | gco1 | gco1 | ss | |||||
2 | gco2 | gco2, ss | ss | gco2 | gco2 | gco1, ss | |||||
3 | gco1 | ss | ss | gco1 | |||||||
4 | ac | gco1 | gco1 | ||||||||
5 | ac | gco1 | ss | gco2 | tu | ss | gco1 | ||||
6 | ac | gco1, ss | ss | ss | ac | ss | gco1 | ||||
7 | ac | gco1 ,ss | ss | ac | ss | gco1 | |||||
8 | ac | gco1, ss | gco2 | ac | gco1 | ||||||
9 | gco1, ss | ss | ss | si | ac | ss | gco1 | ||||
10 | gco1, gco1 | ss | ss | gco1 | |||||||
11 | gco1, gco1 | pe(♂) | ltas(♀) | lts |
The head (Fig.
The neck (Figs
Segment 1 (Figs
Segment 2 (Figs
Segment 3 (Figs
Segment 4 (Figs
Segment 5 (Figs
Segment 6 (Figs
Segment 7 (Figs
Segment 8 (Figs
Segment 9 (Figs
Segment 10 (Figs
Segment 11 (Figs
This species is named after the late Dr. Frank A. Romano III, Jacksonville State University, Alabama, for his contributions to the study of meiofauna and for his initiation of our ongoing meiofauna survey.
Echinoderes romanoi sp. n. is characterized by the presence of middorsal spines on segments 4 to 8, lateroventral tubes on segment 5, lateroventral spines on segments 6 to 9, and glandular cell outlets type 2 on segments 2 (4 pairs), 5, and 8. This combination of spines, tubes, and glandular cell outlets is unique among all species in the genus. The spine/tube arrangement is not unusual among congeners: 36 additional species share the presence of middorsal spines on segments 4 to 8 and lateroventral tubes/spines on segments 5 to 9, and out of these, ten also lack tubes on segment 2 as does E. romanoi sp. n.: Echinoderes angustus
Holotype: Adult male (
Conspicuously small Echinoderes (183–209 µm) with middorsal spines on segments 4, 6 and 8, and spines in lateroventral positions on segments 6 to 9. Tubes present in ventrolateral positions on segment 2, in lateroventral positions on segment 5, and in laterodorsal positions near the posterior margin of segment 10. Glandular cell outlets type 2 present in subdorsal position on segment 2, in midlateral position on segment 6, and in sublateral position on segment 8.
Adults conspicuously small (183–209 µm in trunk length), with head, neck and eleven trunk segments (Figs
Line art illustrations of Echinoderes joyceae sp. n. A Male, dorsal view B Male, ventral view C Female, segments 10 to 11, dorsal view D Female, segments 10 to 11, ventral view. Abbreviations: gco1/2, glandular cell outlet type 1/2; ld, laterodorsal sensory spot; ldt, laterodorsal tube; ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral spine; lvt, lateroventral tube; ml, midlateral sensory spot; pa, pachycyclus; pe, penile spine; sd, subdorsal sensory spot; si, sieve plate; vlt, ventrolateral tube.
Light micrographs showing overviews and details in male holotype
Scanning electron micrographs showing overviews and details in head and trunk morphology of female Echinoderes joyceae sp. n. A Lateral overview B Mouth cone and introvert sector 8 C Head and segments 1 to 2, lateral view D Laterodorsal parts of segments 1 to 6 E Trunk segments 1 to 10, lateral view F Laterodorsal parts of segments 4 to 7 G Detail showing sublateral parts of segments 7 to 9 H Detail showing sub- and laterodorsal parts of segment 10 and left tergal extension of segment 11 I Segments 7 to 11, laterodorsal and caudal view. Abbreviations: gco2, glandular cell outlet type 2; ld, laterodorsal sensory spot; ldt, laterodorsal tube; ltas, lateral terminal accessory spine; lvs, lateroventral spine; lvt, lateroventral tube; mds, middorsal spine; ml, midlateral sensory spot; oos, outer oral style; pd, paradorsal sensory spot; psp, primary spinoscalid; sd, subdorsal sensory spot; sec 8, introvert sector 8; si, sieve plate; sp2–5, spinoscalids of rings 2 to 5; tr, trichoscalid; vlt, ventrolateral tube.
Measurements from light microscopy of Echinoderes joyceae sp. n. (in µm) from the Gulf of Mexico, including number of measured specimens (n) and standard deviation (SD). Abbreviations: (ac): acicular spine; LTAS: lateral terminal accessory spine; LTS: lateral terminal spine; LV: lateroventral; MD, middorsal; MSW-6: maximum sternal width, measured on segment 6 in this species; S: segment lengths; SW-10, standard width, always measured on segment 10; TL: trunk length.
Character | n | Range | Mean | SD |
---|---|---|---|---|
TL | 4 | 183–209 | 195 | 10.90 |
MSW-6 | 4 | 40–46 | 43 | 3.00 |
MSW-6/TL | 3 | 20.4–23.0% | 21.8% | 1.32% |
SW-10 | 4 | 34–37 | 35 | 1.26 |
SW-10/TL | 3 | 16.7–19.4% | 17.8% | 1.38% |
S1 | 4 | 23–26 | 25 | 1.50 |
S2 | 4 | 22–26 | 25 | 1.73 |
S3 | 4 | 23–25 | 23 | 1.26 |
S4 | 4 | 21–26 | 24 | 2.22 |
S5 | 4 | 23–27 | 26 | 1.73 |
S6 | 4 | 25–30 | 28 | 2.22 |
S7 | 4 | 27–31 | 30 | 1.91 |
S8 | 4 | 30–33 | 32 | 1.29 |
S9 | 4 | 30–31 | 31 | 0.58 |
S10 | 4 | 31–33 | 32 | 0.82 |
S11 | 4 | 24–27 | 25 | 1.41 |
MD4 (ac) | 5 | 40–58 | 47 | 7.30 |
MD6 (ac) | 5 | 59–74 | 66 | 6.07 |
MD8 (ac) | 5 | 61–75 | 68 | 7.06 |
LV6 (ac) | 4 | 20–25 | 23 | 2.06 |
LV7 (ac) | 4 | 22–31 | 27 | 3.70 |
LV8 (ac) | 4 | 29–39 | 32 | 5.12 |
LV9 (ac) | 4 | 31–34 | 33 | 1.29 |
LTS | 5 | 72–83 | 79 | 4.66 |
LTS/TL | 4 | 39.3–42.9% | 40.3% | 1.75% |
LTAS | 1 | 24 | N/A | N/A |
Summary of nature and location of sensory spots, glandular cell outlets, tubes and spines arranged by series in Echinoderes joyceae sp. n. Abbreviations: LA: lateral accessory; LD: Laterodorsal; LV: lateroventral; MD: middorsal; ML: midlateral; PD: paradorsal; PV: paraventral; SD: subdorsal; SL: sublateral; VL: ventrolateral; VM: ventromedial; ac, acicular spine; gco 1/2, glandular cell outlet type 1/2; ltas, lateral terminal accessory spine; lts, lateral terminal spine; pe, penile spines; si, sieve plate; ss, sensory spot; tu, tube; (♀), female and (♂), male conditions of sexually dimorphic characters.
Position Segment |
MD | PD | SD | LD | ML | SL | LA | LV | VL | VM | PV |
---|---|---|---|---|---|---|---|---|---|---|---|
1 | ss | ss | |||||||||
2 | gco2 | ss | tu | ||||||||
3 | ss | ||||||||||
4 | ac | gco1 | |||||||||
5 | ss | tu | |||||||||
6 | ac | gco1,ss | gco2 | ac | ss | ||||||
7 | ss | ss | ac | ss | |||||||
8 | ac | gco1,ss | gco2 | ac | gco1 | ||||||
9 | ss | ss | si | ac | ss | gco1 | |||||
10 | ss | tu | |||||||||
11 | ss | pe(♂) | ltas(♀) | lts |
The head (Fig.
The neck (Figs
Segment 1 (Figs
Segment 2 (Fig.
Segment 3 (Figs
Segment 4 (Figs
Segment 5 (Figs
Segment 6 (Figs
Segment 7 (Figs
Segment 8 (Figs
Segment 9 (Figs
Segment 10 (Figs
Segment 11 (Fig.
This species is named after Joyce Wright Landers—the wife of the first author.
Echinoderes joyceae sp. n. is characterized by the presence of middorsal spines on segments 4, 6 and 8, ventrolateral tubes on segment 2, lateroventral tubes/spines on segments 5 to 9, and laterodorsal tubes on segment 10. This combination of spines and tubes is not unusual among congeners, and is shared with five other species: E. bermudensis
This study describes E. romanoi sp. n. and E. joyceae sp. n., and reports the known distribution of the two new species along the northern Gulf of Mexico continental shelf. In common with the previous shelf species reported so far during this long term meiofauna sampling is the broad distribution of the taxa. Echinoderes romanoi sp. n. and E. joyceae sp. n. are distributed across wide regions of the United States’ Gulf shelf, with the location of E. romanoi extending from central Louisiana to western Florida, and with E. joyceae sp. n. extending from Texas to Florida. Similarly, E. augustae, E. skipperae, E. charlotteae, and E. bookhouti (
This research was made possible by a grant from The Gulf of Mexico Research Initiative. Data are publically available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (doi: 10.7266/N7H1300J). The authors thank the staff and students and Troy University (TU) and Jacksonville State University for help with sediment collection and laboratory work. In addition, our thanks go to the researchers at the NMFS/NOAA Pascagoula lab for their help with sediment collection and to Katherine Beaton (TU) for providing Figure