Research Article |
Corresponding author: Eduardo Suárez-Morales ( esuarez@ecosur.mx ) Academic editor: Danielle Defaye
© 2017 Juan Manuel Fuentes-Reinés, Eduardo Suárez-Morales.
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:
Fuentes-Reinés JM, Suárez-Morales E (2017) A new species of Echinolaophonte and record of E. armiger (Gurney, 1927) (Crustacea, Copepoda, Harpacticoida, Laophontidae) from the Caribbean with a key to species. ZooKeys 722: 19-36. https://doi.org/10.3897/zookeys.722.14560
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A new species of the harpacticoid copepod genus Echinolaophonte is described here from specimens obtained during a biological survey of Rodadero Bay, a coastal system in the Colombian Caribbean. This species has been previously recorded as E. armiger Gurney, 1927 in different geographic areas (Indian and Pacific Oceans). The Colombian specimens recognized as E. villabonae sp. n. and true E. armiger are deemed as distinct species based on differences in several features of which the shape of the rostrum and the dorsal spinous process on the prosome are among the most distinctive. These and other characters are shared by specimens recorded as E. armiger from Caroline Islands and Australia that are now incorporated to the new species. The finding of the true E. armiger, previously known only from Egypt, the Texan coast, Brazil, and possibly Bermuda, constitutes the first record of this species in the western Caribbean and a regional range extension. A key to the identification of the 13 known species of the genus is also provided.
Benthic copepods, harpacticoids, littoral, taxonomy
The harpacticoid copepod genus Echinolaophonte Nicholls, 1941, belonging to the family Laophontidae, was erected to contain several species previously assigned to Laophonte. Members of this genus are cosmopolitan, benthic forms (
During a survey of the zooplankton community of Rodadero Bay, a shallow coastal system in the Colombian Caribbean, several male and female specimens of harpacticoid copepods of the genus Echinolaophonte were obtained. The taxonomic examination of these specimens revealed that some of them were assignable to the strict form of E. armiger (Gurney, 1927). Another group of individuals resemble closely E. armigersensu
Biological samples of littoral habitats were obtained from Rodadero Bay, Magdalena, northern Colombia (11°14'10"N, 74°12'06"W) during fieldwork carried out from August 2015 to March 2016, mainly at the inshore areas covered by vegetation (mangrove) and with a bank of oysters. Water salinity, pH, temperature were measured with a multiparameter WTW 350i equipment. Water samples were collected manually using a 25-l bucket at both littoral and limnetic habitats. Samples were then filtered with a plankton net (mesh size = 45 μm) and preserved in 70% ethanol. Copepods were sorted from all the samples and then processed for taxonomical identification including the examination of the whole specimen and dissection of selected appendages. Dissected appendages were mounted on slides with glycerin and sealed with Canada balsam. The specimens were measured in ventral position, from the anterior end of the rostral area to the posterior margin of the caudal rami. Drawings were made with the aid of a camera lucida mounted on an Olympus BX51 compound microscope equipped with Nomarski DIC. Some specimens were prepared for SEM examination with a JEOL LV 5900 microscope at the University of Aguascalientes, Mexico. The process included dehydration of specimens in progressively higher ethanol solutions (60, 70, 80, 96, 100 %), critical point drying, and gold coating following standard methods. The specimens examined were deposited at the Museo de Colecciones Biológicas de la Universidad del Atlántico, Barranquilla-Atlántico, Colombia (UARC) and in the Centro de Colecciones Biológicas of the Universidad del Magdalena-Colombia (
Syn.: Echinolaophonte armiger Nicholls, 1945; Echinolaophonte armiger Vervoort, 1964.
Adult female holotype (UARC290M), male allotype (UARC291M), Rodadero Bay, Magdalena, Colombia, coll. J. Fuentes-Reinés, August-June 2016. Paratypes: five females (UARC292M) and two males (UARC293M) from same locality, coll. Juan M. Fuentes-Reinés. Two adult females, two adult males from same locality, date, and collector; specimens dissected, semi-permanent slides (UARC302M–UARC315M). Non-type specimens: two adult females, one adult male in collection of first author (JMFR), one female prepared for SEM analysis, same collection data.
Rodadero Bay, Magdalena, northern Colombia (11°14'10"N, 74°12'06"W).
Body cylindrical, rostrum wide, subrectangular, medially flat, posterior margin of cephalic shield with strong dorsal spiniform which possess two notches. Female antennule six-segmented; male antennule subchirocer, seven-segmented. Antenna three-segmented, EXP one-segmented with four strong setae, inner longest. Mandible ENP and EXP reduced, with three and one short pinnate setae, respectively. Maxillule with well-developed arthrite and eight distal elements; EXP one-segmented, with two apical setae. Maxilliped three-segmented, endopodal claw with single seta. P1-P4ENP and EXP being two and three-segmented, respectively, but P1EXP two-segmented. P1ENP 7.5 times as long as wide. Female and male P5 with long setophore and apical seta, female P5 EXP and ENP with three and four setae, respectively, male P5EXP with three setae. Female and male caudal rami with seven setae.
Female. Habitus as in Figure
Cephalothorax with smooth posterior margin; lateral posterior corners of cephalic shield produced into triangular expansions (Fig.
Echinolaophonte villabonae sp. n., adult holotype female from Colombia. A habitus, lateral view B cephalosome dorsal process, lateral view, arrows indicate notches C same, another specimen D cephalosome showing cuticular indentations on posterolateral margin (arrows), dorsal view E genital double, postgenital and preanal somites, dorsal view F detail of dorsal process on post-genital double-somite G detail of dorsal process, posterior genital double-somite H genital double-somite, ventral view showing sixth legs and genital pore (arrowed) on medial anterior margin. Scale bars: 200 μm(A); 5 μm (B–G).
Caudal rami 1.4–1.9 times longer than wide; each ramus with seven setae: setae I–III bare, first one shortest, setae IV and V pinnate, fused at base, seta VI approximately half-length of seta IV, seta VII articulated (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
Maxilliped (Figs
Echinolaophonte villabonae sp. n. , adult holotype female from Colombia. A antennule B rostrum showing surface ornamentation and marginal rounded protuberances (arrowed) C antenna D antennary exopod, detail E mandible F maxillule G maxilla H maxilliped I caudal rami showing setae I–VII, dorsal view. Scale bars: 25 μm.
P1 (Fig.
P2 (Fig.
P3 (Fig.
P4 (Fig.
Basis | Exopod | Endopod | |
P2 | 1-0 | I-0;I-1;II,2,2 | 0-0;2,1 |
P3 | 1-0 | I-0;I-1;I,I-2,2 | 0-0;2,2 |
P4 | 1-0 | I-0;I-1;I,I-2,2 | 0-0;2,1 |
P5 (Fig.
P6 (Fig.
Male. Habitus resembling that of female but somewhat smaller. Total body length measured from anterior margin of rostrum to posterior margin of caudal rami ranging from 476 to 508 μm (average = 478 μm, n = 7; holotype: 476 μm).Cephalosome with strong dorsal spiniform at median posterior margin of cephalic shield as in female (Fig.
Antenna, mandible, maxillule, and maxilla as in female. Maxilliped as in female (Fig.
P4 (Fig.
P5 (Fig.
P6 (Fig.
Caudal rami 1.5–1.6 times as long as wide (Fig.
Echinolaophonte villabonae sp. n., female from Colombia, SEM-prepared specimen. A cephalothorax, lateral view B dorsal process on cephalic shield showing distinctive notches (arrowed) C detail of cephalic shield marginal ornamentation D pedigerous somites 2–5, lateral view E antenna F detail of distal elements of antenna G urosome and caudal rami, lateral view, caudal seta VII arrowed.
The species is named after Dr. Silvia Lucía Villabona-González, for her intense research on the zooplankton communities of Colombia and for her legacy and leadership of new generations of planktologists in this country.
The genus Echinolaophonte was divided by
The redescription of E. armiger based on type material from the Suez Canal, Egypt supported the notion that only a few of the previous records of E. armigersensu
The new species, Echinolaophonte villabonae sp. n. can be distinguished from E. armiger Gurney, 1927 by several characters:1) the rostrum has two protuberances in its anterior margin in E. villabonae (Fig.
The new species most closely resembles E. gladiator Vervoort, 1964 and E. tropica Ummerkutty, 1970. They share an identical armature formula of P1–P4. The female fifth leg armature, with 3 and 4 setal elements on the fifth leg EXP and ENP, respectively also resembles the pattern found in E. gladiator (
This species is known to be associated mainly with coral reef areas. It has been reported (as E. armiger) from the reef area at Port Denison, Australia (
Syn. Laophonte armiger Gurney, 1927: 554–556, fig. 159;
One dissected adult female (
Female. Habitus as in Figure
Antennule (Fig.
Mandible, maxillule, maxilla, and maxilliped (Fig.
P1 (Fig.
P5 (Fig.
Male. Habitus resembling that of female (Fig.
P1 (Fig.
A–O Echinolaophonte armiger (Gurney) from Colombia, unscaled digital micrographs. Adult female (body length = 644 μm). A habitus, lateral view showing dorsal process on cephalic shield (arrow) B rostrum showing flat anterior surface and depressed distal margins C process on cephalic shield, lateral view D antennule E antenna F detail of antennary exopod G cephalosome showing weak development of posterolateral margins (arrows), dorsal view H maxillule showing slender inner seta on syncoxa (arrowed) I leg1 J leg 5; adult male (body length 560 μm) K habitus, lateral view showing smooth dorsal process on cephalosome L antennule M leg1 N leg 5 O leg 6.
One male was observed to have three setal elements on the antennal exopod instead of the usual pattern of four.
The present record, from the Caribbean coast of Colombia, is the fifth of E. armigersensu Gurney, 1927 worldwide. In the surveyed area this species coexists with the closely related E. villabonae, which is locally more abundant.
Suez Canal, Egypt (type locality), the Texan coast (USA) (
1 | Spinal formula of outer spines on P2-P4 EXP3 = 332 or 232 | 5 |
– | Spinal formula of outer spines on P2-P4 EXP 3 = 222 or 333 | 2 |
2 | Spinal formula of outer spines on P2-P4 EXP 3 = 222 | 3 |
– | Spinal formula of outer spines on P2-P4 EXP 3 = 333 | E. mirabilis (Gurney, 1927) |
3 | Dorsal spiniform process present on cephalic shield, P2ENP reaching halflength of EXP3, length/width ratio of P1 ENP between 4.5 and 5.8 | 4 |
– | Dorsal spiniform process on cephalothorax absent, P2ENP reaching inner seta of P2EXP2, length/width ratio of P1 ENP = 4.4 | E. tropica Ummerkutty, 1970 |
4 | Dorsal spiniform process with two distinctive notches on posterior margin, second segment of antennule without particular features, length width ratio of P1 ENP = 7.5. | E. villabonae sp.n. |
– | Dorsal spiniform process smooth, lacking notches on posterior margin, second segment of antennule with strong, outwardly directed hook, length/width ratio of P1 ENP = 5.8 | E. gladiator (Vervoort, 1964) |
5 | Spinal formula of P2-P4 = 232, male P3 ENP with or without apophysis | 6 |
– | Spinal formula of P2-P4= 332, male P3 ENP with or without apophysis | 8 |
6 | Baseoendopod of female P5 with 2 inner setae; EXP3 P2 as long as segments 1-2 combined. EXP2-3 P2 lacking inner setae | E. minuta Cottarelli & Forniz, 1991 |
– | Baseoendopod of female P5 with single inner seta; EXP1-3 P2 subequal in length. EXP2-3 P2 with inner setae | 7 |
7 | P4 ENP shorter than EXP1, rostrum reverse trapezoid, small, body size 580 µm (female), 490 µm (male) | E. hystrix (Brian, 1928) |
– | P4 ENP longer than EXP1, rostrum rectangular, body size 618-650 µm (female), 565 µm (male) | E. armiger (Gurney, 1927) |
8 | Female P5ENP with four setae, maxillule with endopod | 9 |
– | Female P5ENP with two setae, maxillule lacking endopod | E. veniliae Cottarelli, Forniz & Bascherin, 1992 |
9 | Caudal rami length/width ratio 4 times as long as wide, male P3 ENP lacking apophysis | E. tetracheir Mielke, 1981 |
– | Caudal rami length/width ratio between 3.1 and3.4 times as long as wide, EXP2 P2 with two setal elements, inner seta and outer spine; EXP3 P2 with inner seta | 10 |
– | Caudal rami length/width ratio ranging between 2.0 and 2.2 times as long as wide, EXP2 P2 with one setal element, inner seta absent, EXP3 P2 lacking inner seta | 11 |
10 | P1 EXP reaching halflength of ENP1, P2ENP1 not reaching distal end of EXP1, rostrum bilobed at tip, male P3EXP2-3 inner setae long | E. brevispinosa Sars, 1908 |
– | P1 EXP relatively short, reaching ¼ the length ENP1, P2ENP1 reaching distal end of EXP1, rostrum rounded at tip, male P3EXP2-3 inner setae short | E. horrida (Norman, 1876) |
11 | P2 ENP2 with medial distal seta spiniform, clearly shorter than adjacent two distal setae, half the length of bearing segment. P1 ENP1 lacking inner seta | E. longantennata Apostolov, 1990 |
– | P2 ENP2 with medial distal seta setiform, as long as adjacent 2 setae. P1 ENP1 with inner seta | E. oshoroensis Itô, 1969 |
Marcelo Silva-Briano and Araceli Adabache (Universidad de Aguascalientes, Mexico) kindly processed the SEM examination of specimens of both E. armiger and of the new species. We thank Wonchoel Lee (Hanyang University, Korea) for his advice and encouragement during the process of defining the new species with respect to E. armiger.