Crustacea: Cephalocarida) from the West Coast of Florida

BULLETIN OF MARINE SCIENCE, 26(4): 593.599, 1976

A NEW SPECIES OF LIGHTIELLA (CRUSTACEA: CEPHALOCARIDA) FROM THE WEST COAST OF FLORIDA

Patsy A. McLaughlin

ABSTRACT A new species of cephalocarid from the west coast of Florida, Ligh/iella floridana, is described, illustrated, and compared with other species of the genus. This species repre- sents the eighth cephalocarid species to be recognized and the first species known to occur in the Gulf of Mexico.

The subclass Cephalocarida was estab- Upon collection, the samples were preserved lished slightly more than 2 decades ago as in 10% seawater formalin buffered with the result of the discovery of a unique "Borax." After sorting in the laboratory, crustacean, Hutchinsoniella macracantha the specimens were transferred to 45% iso- Sanders, 1955, in the bottom sediments of propyl alcohol for storage and subsequent Long Island Sound. Subsequently, benthic examination. Although the cephalocarids studies in various parts of the world have appeared opaque or white in formalin or contributed six other species, representing alcohol, when mounted in a medium of poly- two additional distinct genera of this prim- vinyl-alcohol-Iactophenol, they became quite itive crustacean group. These species in- transparent and morphological characters clude Lightiella serendipita Jones, 1961, often were difficult to distinguish. Conse- from San Francisco Bay, California, L. in- quently, a number of specimens were stained cisa Gooding, 1963, from Barbados, other with a 0.1% Chlorazol Black E solution in localities in the Caribbean Sea, and one lactophenol (3% by volume) and heated larva from Biscayne Bay, Florida, L. mon- for 1 to 2 hours at 65°C (cf. Monod and niotae Cals and Delamare Deboutteville, Cals, 1970) before dissection and mounting. 1970, from New Caledonia, Sandersiella In the descriptions of their species of acuminata Shiino, 1965, from Kyushu and Lightiella, both Jones (1961) and Gooding the Seto Inland Sea, Japan, S. calmani (1963) referred to the armature of the en- Hessler and Sanders, 1973, from the coast dites and the terminal segments of the endo- of Peru, and S. bathyalis Hessler and San- pods as consisting of spines plus setae or ders, 1973 from off Walvis Bay, southwest simply spines. Similarly, Gooding referred Africa. During the course of a benthic sur- to the single short seta on the dorsal margin vey of the Anclote Anchorage, Florida, be- of each distal exopodal segment as a spine. ing conducted by Applied Marine Ecolog- Hessler and Sanders (1973), in referring ical Services, Inc., under the auspices of to the spines on the terminal segments of Florida Power Corporation, one additional the endopods, have called them claws, and new species of the genus Lightiella has been have made no distinction between spines discovered. and setae on the endites. The short setae on With the exceptions of two specimens the dorsal margins of the distal exopodal fortuitously caught up in algal mats col- segments have been referred to by these lected by trawling gear, all specimens have latter authors as "short setae intercalated into been obtained with a 15 x 15 em "benthos [the] setal row." Although no attempt has sampler" similar in construction to that of been made during the present study to de- a post-hole digger (Baird, et a1. 1971). termine whether the various types of arma-

593 594 BULLETIN OF MARINE SCIENCE, VOL. 26, NO.4, 1976 ture observed truely represent spines or Lightiella floridlllUl new species setae, it is my belief that some differentia- Holotype.-Adult, 2.6 mm, ovigerous, tion should be made. Therefore, stout USNM 156312; Station 30, 28° 10'50"N, "spine-like" structures on the endites of the 82°48'52"W, Anclote Anchorage, Florida, protopods and the terminal segments of 0.75-2.25 m. the endopods are referred to as spines and indicated in the tables by Roman numerals. Paratypes.-50 adults, 3 ovigerous, 2.1-3.0 The short seta occurring on the dorsal mar- mm, from type locality (USNM, AHF, gin of each distal exopodal segment has RMNH); 1 adult, 2.4 mm, station 29, been indicated by a bracket. 28°10'45"N, 82°48'30"W, 1.0-1.25 m The holotype and several paratypes have (RMNH); 2 adults, 1.8, 2.0 mm, station been deposited in the collections of the Na- 21, 28°11'25"N, 82°48'7"W, 0.75-1.5 m tional Museum of Natural History, Smith- (USNM); 4 adults, 1 ovigerous, 2.3-2.6 mm, sonian Institution (USNM). Additional station 15, 28°11'45"N, 82°48'30"W, 2.0- paratypes have been deposited in the col- 2.25 m, Andote Anchorage, Florida (MCZ), lections of the Allan Hancock Foundation, January through May 1976. University of Southern California (AHF), the Museum of Comparative Zoology, Har- Description.-Body (Fig. lA) with anterior vard University (MCZ), and the Rijksmu- and anterolateral margins of cephalon bear- seum van Natuurlijke Historie, Leiden, The ing short fine setae and occasionally very Netherlands (RMNH). short stiff bristles. Pleura of first seven thoracic segments truncate or broadly rounded; pleuron of eighth thoracic segment Lightiella Jones reduced to small spinose process. Pleura of Type species.-Lightiella serendipita Jones, pretelsonic segments developed into mod- 1961, by monotypy. erately strong spinose processes. Telson (Fig. lA) with well developed pair of ter- Diagnosis.-Eighth thoracic segment lack- minal dorsal spines; ventral comb (Fig. 1B) ing appendages; pleuron sometimes re- with strong teeth. Caudal rami equalling duced or lacking. Telson only abdominal or exceeding width of telson, usually equal- segment with vertical comb; comb row ex- ling combined length of last two abdominal tends full width of abdomen. Caudal rami segments; with one or two short and two moderately short, usually not exceeding moderately long terminal setae. combined length of last two abdominal seg- Ratio of distal four segments of antennule ments. (Fig. 1C) approximately 2: 1:1:2 (proximal to distal); first, fourth and fifth seg- KEY TO THE SPECIES OF LICllTIELLA ments without setae, second segment with two moderately short setae, third with four 1a. Telson with dorsal terminal spines 2 or five moderately short to long setae, ter- 1b. Telson without dorsal terminal spines ______L. sere/I dipiIa minal segment with six to eight short to 2a. Incisor process of mandible with 2 promi- moderately long setae and one long, multi- nent teeth; pleurae of 8th thoracic segment articular sensory flagellum ("aesthete" of represented by small spinose processes 3 2b. Incisor process of mandible with 1 promi- Gooding, 1963). nent tooth; pleurae of 8th thoracic segment Antenna (Fig. 1D) with one short seta absent . .. L. incisa on margin of propodite. Endopod with one 3a. Caudal rami considerably shorter than combined length of last 2 abdominal seg- short and one long seta on proximal segments __. . .._. L. lI1onniolae ment, distal segment with one large and 3b. Caudal rami approximately equal to com- one small spine and three setae terminally. bined length of last 2 abdominal segments L. floridana Exopod with 19 or 20 segments; setal for- McLAUGHLIN: A NEW SPECIES OF LIGHT/ELLA FROM FLORIDA 595

I---f A ...--- ••, B-G B

Figure 1. Lighlie/la floridana n. sp. in dorsal view (appendages and caudal setae omitted): (B) Telson and caudal rami (ventral view); (C, D, F, G) Cephalic appendages (left); (C) antennule; (D) antenna; (F) mandible; (G) 1st maxilIa; (E) Labrum (ventral view). Scales equal 0.1 (A) and 0.05 (B-G) mm. [Detailed setation omitted]

mula most commonly 2,2,1,2,0,1,1,1,1,1,1, Mandible (Fig. IF) with incisor process 3,3,1,2,1,1,1,4. consisting of pair of strong teeth and one Labrum (Fig. IE) large, broadly rounded median serrate seta; frequently with one to anteriorly, acutely triangular posteriorly, and three minute denticles on ridge separating with median transverse suture; anteroven- molar from incisor process; molar process tral surface with several irregular and inter- with eight or nine small teeth and two rupted rows of minute denticles; postero- stronger teeth near angle, lower margin with ventral surface with three short transverse short setae. rows of very small teeth. First maxilla (Fig. 1G) with eight setae 596 BULLETIN OF MARINE SCIENCE , VOL 26, NO . 4, 1976 McLAUGHLIN: A NEW SPECIES OF LIGHT/ELLA FROM FLORIDA 597

Table I. Armature of protopodal endites':' ----~----- ~--- II III IV V VI

Maxilla 2 4-6 I 1-2 II 1-2 I-II 2-3 0-3 0-3 Thoracopod I 6-9 I-II 2-5 II 3-5 I-II 3 1-3 1-3 Thoracopod 2 4-6 III 3-6 II 4-6 I-II 2-3 I 2-3 2-3 Thoracopod 3 4-6 1II 4-5 II-III 3-7 II 4-5 I 3-4 2-3 Thoracopod 4 4-7 III 3-6 III 3-6 II 3-4 I 3-4 2-3 Thoracopod 5 4-5 I-II 4-6 III 3-6 II 0-4 0-1 3 2-3 Thoracopod 6 1-2 I 3-4 II 3-4 II 0-2 0-1 2-3 2-3 Thoracopod 7 ? 1 (?)1 (?)2 (?)1 (1)1 • N = 10. on distal lobe of exopod. Endopod with gins entire. Pseudepipods with four or five one seta on each of two proximal segments; marginal plumose setae; posterior faces three strong spines on terminal segment. moderately hirsute. Gnathobase usually with four, occasionally Habitat.-Lightiella floridana appears to be only with three, terminal setae; occasionally a very shallow water species inhabiting areas also with one subterminal seta. of the Anchorage that are characterized by Second maxilla (Fig. 2A) and thoraco- a fine quartz sediment overlain with or- pods] -7 (Figs. 2B-H) with some variation ganic matter and flocculent material. The in setation and armature (Tables 1 and 2). predominant vegetation is Thalassia sp. Dur- Second maxilla and first six thoracopods ing the 5-month period in which the speci- each with six protopodal enditic processes mens have been collected, temperatures (I-VI, proximal to distal); thoracopod 7 ranged from 11.7° to 25.5°C at the bottom, with fOllr processes. Endite I of second and salinities varied from 24.0 to 34.51,r. A maxilla and each thoracopod (1-6) with decrease in dissolved oxygen (13.3 ppm in one prominent, hooked and serrated spine, thoracopods also with marginal circlet of January to 5.5 ppm in May) has also been observed. minute spinules; internal faces of thoracopods 2-4, and occasionally also 1 and 5, Discussion.-Of the four species of Light- each with one or two small accessory spines. iella now recognized, only L. serendipita Second endites characteristically with two lacks a terminal pair of dorsal spines on the large serrated spines and on thoracopods 3- telson, and this character immediately dis- 5 usually one accessory spine. Distolateral tinguishes it from the other species. In sev- angles of protopods usually denticulate or eral respects L. floridana appears more spinulose. Terminal segment of endopod of closely related to L. monniotae from the second maxilla with two strong spines and south Pacific than to its Caribbean neighbor, two small accessory spines; terminal seg- L. incisa. With the former species, L. flor- ments of thoracopods 2-5 each with three idana shares the character of a bidentate strong spines and single small accessory mandibular incisor and the development of spine, thoracopods 5 and 6 each with two the pleura of the eighth thoracic segment into strong spines, accessory spine on thoraco- a small spinose lateral process. Cals and pod 6 occasionally absent; terminal segment Delamare Deboutteville (1970) suggest that of thoracopod 7 with one long seta and one the mandible in L. monniotae may consist of very small spine. Dorsal margin of each two segments. A similar situation was orig- endopodal segment with row of very short inally thought to exist in L. floridana; how- setae. Exopods with posterior faces of dis- ever, detailed examinations of several tal segments somewhat setose, lateral mar- stained specimens have not confirmed this. 598 BULLETIN OF MARINE SCIENCE, VOL. 26, NO.4, 1976

Table 2. Setation formula*

Endopodal Segments

Pseudepipod Exopod II III IV V

Maxilla 2 4-5 4 8-9 [I] 4 1-2 2-4 2 4 II 2a Thoracopod 5 3 8-10 [I] 4 2-3 3-4 2-3 4 III a Thoracopod 2 5 3 8-9 [I] 4 2-4 3-4 3 4 III a Thoracopod 3 5 3 8-9 [I] 4 3 3-4 3 4 III a Thoracopod 4 5 3 8-9 [I] 4 3 3-4 3 4 III a Thoracopod 5 5 3 6-8 [I] 4 1-3 3-4 3 4 II a Thoracopod 6 5 2-3 5-7 [I] 4 2-3 3-4 2 1-2 II (a) Thoracopod 7 4 1-2 5-6 [I] 4 1 1-2 1-3 0-1 la • N = 15.

A moderate amount of variation in the seta- The specific name, floridana, both reflects tion of the cephalic and thoracic appendages the geographical occurrence of the species has been found in L. floridana and, as a re- and acknowledges the support of this in- sult, the setation formulae in some instances vestigation by Florida Power Corporation. overlap those of L. incisa. Such variation is not unexpected, however, and similar ACKNOWLEDGMENTS variations in setal formulae have been re- This study has been supported by Florida Power ported in the other two genera, i.e., H. Corporation (FPC), under the auspices of the macracantha (Hessler and Sanders, 1964; Environmental Protection Agency (EPA), through Wakabara, 1970) and S. bathyalis (Waka- a contract with Applied Marine Ecological Ser- vices, Inc. (AMESI). The author gratefuUy ac- bara and Mizoguchi, 1976). Hessler and knowledges this support and the permission granted and Sanders (1973) also have reported on by both FPC and AMESI to publish on this variations in both setation and segmenta- material. The efforts of a number of AMESI tion of the antenna in L. incisa. technicians, particularly those of Mrs. Tina M. Folkman, to collect and sort out specimens of L. Several characters, that appear to be quite jlorida/la, have contributed substantiaUy to this stable, may be used to distinguish L. flor- study. The author also wishes to express her ap- idana from L. incisa. These include the bi- preciation to Dr. Howard L. Sanders, Woods Hole dentate mandibular incisor process, small Oceanographic Institution, for the loan of com- spinose processes on the eighth thoracic seg- parative material of L. incisa, and to Dr. Meredith L. Jones, National Museum of Natural History, ment, stronger spinose processes on the pre- Smithsonian Institution, for his many helpful sug- telsonic abdominal segments, longer caudal gestions and review of the manuscript. rami and the absence of notches on the lateral margins of exopodal segments of the LITERATURE CITED thoracic appendages in L. floridana. In con- Baird, R. C., K. L. Carder, T. L. Hopkins, T. E. trast, the mandibular incisor process in L. Pyle, and H. J. Humm. 1971. Andote En- incisa consists of a single tooth and small vironmental Project Report, 1971. Marine denticles, the pleurae are lacking on the Science Institute, University of South Florida, Technical Report. 251 pp. eighth thoracic segment, the pretelsonic ab- Cals, P., and C. Delamare Deboutteville. 1970. dominal segments bear very small spinose Une nouvelle esp(:ce de Crustace Cephalo- processes, the caudal rami are considerably caride de I'Hemisphere austral. C. R. Acad. shorter than the combined length of the Sci. 270: 2444-2447. Gooding, R. U. 1963. Lightiella incisa sp. nov. last two abdominal segments, and the lat- (Cephalocarida) from the West Indies. Crus- eral margins of distal segments of the exo- taceana 5: 293-314. pods of thoracopods 2 through 5 are prom- Hessler, R. R., and H. L. Sanders. 1964. The discovery of Cephalocarida at a depth of 300 inently notched, meters. Crustaceana 7: 77-78. McLAUGHLIN: A NEW SPECIES OF LIGHT/ELLA FROM FLORIDA 599

1973. Two new species of Sandersiella et sp. nov., a cephalocarid from Japanese (Cephalocarida), including one from the deep waters. Crustaceana 9: 181-191. sea. Crustaceana 24: 181-196. Wakabara, Y. 1970. Hutchinsoniella macracan- Jones, M. L. 1961. Lighliella serendipila gen. Ilia Sanders, 1955 (Cephalocarida) from Bra- nov., sp. nov., a cephalocarid from San Fran- zil. Crustacean a 19: 102-103. cisco Bay, California. Crustaceana 3: 31-46. ---, and S. M. Mizoguchi. 1976. Record of Monod, Th., and P. Cals. 1970. Mission zo- Sandersie/la balhyalis Hessler and Sanders, ologique BeIge aux iles Galapagos et en Ecua- 1973 (Cephalocarida) from Brazil. Crusta- dor. 2: 57-103. ceana 30: 220-221. Sanders, H. L. 1955. The Cephalocarida, a new subclass of Crustacea from Long Island ADDRESS: Departmenl of Biological Sciences, Sound. Proc. nation. Acad. Sci. 41: 61-66. Florida Inlemational University, Tamiami Trail, Shiino, S. M. 1965. Sandersie/la acuminata gen. Miami, Florida 33199.