Astropecten mcedwardi, Cobb & Lawrence & Herrera & Lopez & Janies, 2019

Cobb, Janessa C., Lawrence, John M., Herrera, Joan C., Lopez, Karen & Janies, Daniel, 2019, A new species of Astropecten (Echinodermata: Asteroidea: Paxillosida: Astropectinidae) and a comparison of the Astropecten species from the Gulf of Mexico and the East Florida Shelf, Zootaxa 4612 (3), pp. 301-325 : 303-309

Astropecten mcedwardi , n. sp.

Figures 1–2 , 5a , 6a , 8a , 9b

Diagnosis. A small species (R <30 mm) of Astropecten with five short arms and a wide disk. The surface of the IM plates are bare except for long acute spines along the margins and one or two tubercles in the center of the plate. IM plates with one or two compressed fringe spines. Adambulacral plates with two rows of acute spines, of which the middle spine of each row is longest. The middle spine of the second row (first row of subambulacral spines) often exceeds the length of the middle spine of the first row (furrow spines). Superomarginal plates are small with length approximately equal to width. Spines usually present on the interradial SM plates. Paxillae are not dense and have slender rugose spinelets. Living specimens are pale pink, pale orange, or white, and each arm has a dark line along its dorsal axis. SM spines and fringe spines may have a light orange band at their base.

Materials examined. Holotype. USNM 1551002 , n = 1 wet specimen, 24°49.78′N 82°51.22′W, 42m, Dry Tor- tugas, Gulf of Mexico. R = 27.1 mm, r = 8.9 mm.

Paratypes. Gulf of Mexico (east of De Soto Canyon )— FSBC I 117245 n = 101 dry specimens, 26°24.00′N 82°58.00′W, 37m ; FSBC I 122362 n = 1 wet specimen, 29°42.85′N 86°02.43′W, 46m ; FSBC I 122364 n = 1 wet specimen, 28°55.50′N 84°52.23′W, 46m ; FSBC I 131431 n = 1 wet specimen, 25°15′N 82°55′W, 49m ; FSBC I 131433 n = 1 wet specimen, 25°03′N 83°11′W, 61m ; FSBC I 131436 n = 3 wet specimens, 25°23′N 83°14′W, 61m ; USNM 1551004 , n = 1 wet specimen, 24°49.78′N 82°51.22′W, 42m ; USNM 1551005 , n = 1 wet specimen, 24°49.78′N 82°51.22′W, 42m ; USNM 1551006 , ex. FSBC I 117245 n = 50 dry specimens, 26°24.00′N 82°58.00′W, 37m .

Other nontype specimens; number of specimens measured in parentheses: Eastern Atlantic ( East Florida Shelf)— FSBC I 130783 n = 4 28°04′N 80°01′W ; FSBC I 130782 n = 5 28°07′N 80°03′W ; FSBC I 133475 n = 7 28°07′N 80°04′W ; USNM E43554 n = 33(1) 28°15′N 80°05′W ; FSBC I 075787 n = 1 28°37′N 80°05′W ; FSBC I 117252 n = 4 27°44′N 80°06′W ; FSBC I 054492 n = 3(1) 27°45′N 80°06′W ; FSBC I 130785 n = 5 28°22′N 80°06′W ; FSBC I 117266 n = 5 28°30′N 80°06′W ; FSBC I 133477 n = 1 28°30′N 80°09′W ; FSBC I 133476 n = 1 28°10′N 80°11′W ; FSBC I 130786 n = 1 28°40′N 80°11′W ; FSBC I 133478 n = 5 28°43′N 80°12′W ; FSBC I 075412 n = 1, FSBC I 075652 n = 1, FSBC I 075785 n = 2, FSBC I 075864 n = 1, FSBC I 076098 n = 1, FSBC I 082155 n = 1 28°31′N 80°13′W ; FSBC I 073328 n = 1, FSBC I 076699 n = 1 28°35′N 80°13′W ; FSBC I 130787 n = 5 28°54′N 80°14′W ; FSBC I 054493 n = 67(1) 29°20′N 80°14′W ; FSBC I 054496 n = 4 29°10′N 80°17′W ; FSBC I 128594 n = 1 29°42′N 80°17′W ; FSBC I 117138 n = 3 29°35′N 80°19′W ; FSBC I 117263 n = 3, FSBC I 117275 n = 2 28°32′N 80°20′W ; FSBC I 133479 n = 1 29°06′N 80°20′W ; FSBC I 130784 n = 1 28°07′N 80°22′W ; FSBC I 133480 n = 1 30°30′N 80°51′W ; FSBC I 070262 n = 1 GPS n/a. Gulf of Mexico (east of De Soto Canyon)— USNM E18550 n = 18 24°35′N 81°06′W ; FSBC I 126851 n = 1 24°47′N 81°49′W ; FSBC I 071397 n = 1 26°24′N 82°06′W ; FSBC I 132648 n = 3 24°48′N 82°09′W ; FSBC I 102817 n = 2 26°02′N 82°10′W ; FSBC I 128067 n = 2 25°06′N 82°14′W ; FSBC I 126850 n = 1 24°45′N 82°17′W ; FSBC I 102822 n = 3(1) 25°02′N 82°17′W ; FSBC I 122375 n = 3 24°46′N 82°22′W ; FSBC I 115756 n = 1 25°10′N 82°24′W ; FSBC I 073327 n = 1 24°33′N 82°27′W ; FSBC I 109137 n = 1 24°56′N 82°28′W ; FSBC I 117269 n = 1 26°24′N 82°28′W ; FSBC I 128068 n = 3 25°01′N 82°29′W ; FSBC I 131426 n = 6 24°57′N 82°30′W ; FSBC I 117236 n = 2 25°11′N 82°30′W ; FSBC I 082064 n = 5 24°47′N 82°31′W ; FSBC I 117239 n = 9 25°31′N 82°32′W ; FSBC I 131427 n = 1 24°46′N 82°33′W ; FSBC I 082015 n = 1 25°54′N 82°33′W ; FSBC I 114116 n = 3 26°03′N 82°34′W ; FSBC I 129191 n = 5 25°02′N 82°36′W ; FSBC I 072984 n = 2 25°12′N 82°36′W ; FSBC I 082063 n = 3 25°20′N 82°36′W ; FSBC I 082012 n = 1 24°39′N 82°38′W ; FSBC I 082061 n = 5 24°58′N 82°38′W ; FSBC I 135105 n = 2 24°53′N 82°40′W ; FSBC I 077292 n = 1 25°00′N 82°40′W ; FSBC I 122374 n = 4 24°47′N 82°41′W ; FSBC I 131430 n = 1 25°49′N 82°41′W ; FSBC I 082058 n = 10 25°02′N 82°42′W ; USNM E18569 n = 11 24°24′N 82°43′W ; FSBC I 069566 n = 1 26°15′N 82°43′W ; FSBC I 126849 n = 4 24°53′N 82°44′W ; FSBC I 122376 n = 2 25°00′N 82°44′W ; FSBC I 068177 n = 2 26°07′N 82°44′W ; FSBC I 131435 n = 1 25°41′N 82°46′W ; FSBC I 122378 n = 1 26°07′N 82°46′W ; FSBC I 129192 n = 1 25°08′N 82°47′W ; FSBC I 102821 n = 3 25°57′N 82°47′W ; FSBC I 082066 n = 4 25°08′N 82°48′W ; UF 009016 n = 1 25°09′N 82°48′W ; FSBC I 132646 n = 5 24°56′N 82°49′W ; FSBC I 072907 n = 1, FSBC I 072990 n = 1 25°42′N 82°50′W ; FSBC I 102820 n = 2 25°12′N 82°51′W ; FSBC I 131428 n = 5 24°50′N 82°52′W ; FSBC I 109136 n = 1 24°58′N 82°52′W ; FSBC I 131432 n = 1 25°02′N 82°52′W ; FSBC I 069564 n = 1 26°20′N 82°52′W ; FSBC I 068171 n = 2 26°21′N 82°52′W ; FSBC I 082068 n = 1 27°01′N 82°52′W ; FSBC I 082082 n = 3 24°49′N 82°55′W ; FSBC I 073445 n = 1 26°10′N 82°55′W ; FSBC I 132650 n = 2 26°12′N 82°55′W ; FSBC I 102818 n = 1 24°55′N 82°56′W ; FSBC I 128073 n = 1 25°31′N 82°56′W ; FSBC I 129198 n = 1 25°39′N 82°56′W ; FSBC I 082067 n = 2 26°27′N 82°56′W ; FSBC I 117241 n = 1 26°30′N 82°56′W ; FSBC I 132651 n = 2 26°59′N 82°56′W ; FSBC I 109140 n = 1(1), FSBC I 117257 n = 2 27°05′N 82°56′W ; FSBC I 113435 n = 5 25°51′N 82°57′W ; FSBC I 128071 n = 4 26°10′N 82°58′W ; FSBC I 005769 n = 3, FSBC I 070261 n = 1(1), FSBC I 070268 n = 3, FSBC I 070270 n = 2, FSBC I 070273 n = 6, FSBC I 070297 n = 1(1), FSBC I 070299 n = 3, FSBC I 070309 n = 2, FSBC I 070317 n = 52, FSBC I 070324 n = 35, FSBC I 070325 n = 38(1), FSBC I 070329 n = 1, FSBC I 070335 n = 14, FSBC I 070338 n = 2, FSBC I 070450 n = 10, FSBC I 070451 n = 9, FSBC I 070457 n = 2, FSBC I 070459 n = 2, FSBC I 070460 n = 5, FSBC I 070478 n = 4, FSBC I 070641 n = 65, FSBC I 070642 n = 9, FSBC I 071375 n = 5, FSBC I 071376 n = 14(2), FSBC I 071379 n = 27, FSBC I 071380 n = 36, FSBC I 071392 n = 4, FSBC I 071403 n = 6, FSBC I 071407 n = 66, FSBC I 071408 n = 15, FSBC I 077274 n = 1, FSBC I 077275 n = 1, FSBC I 117250 n = 1, FSBC I 117251 n = 1, FSBC I 117253 n = 5, FSBC I 117255 n = 3, FSBC I 117256 n = 1, FSBC I 117259 n = 18, FSBC I 117262 n = 2, FSBC I 117265 n = 5, FSBC I 117268 n = 1, FSBC I 117271 n = 27, FSBC I 117272 n = 3, FSBC I 117326 n = 4, FSBC I 132089 n = 1 26°24′N 82°58′W ; FSBC I 128072 n = 1 25°36′N 82°59′W ; FSBC I 069565 n = 13(1) 26°12′N 82°59′W ; FSBC I 072997 n = 4 26°20′N 82°59′W ; FSBC I 076698 n = 3, FSBC I 127465 n = 1 26°00′N 83°00′W ; FSBC I 072991 n = 1 26°33′N 83°00′W ; UF 010786 n = 13 26°19′N 83°01′W ; FSBC I 109123 n = 1 26°22′N 83°01′W ; FSBC I 068176 n = 4 26°23′N 83°01′W ; FSBC I 082072 n = 4 26°35′N 83°01′W ; FSBC I 067363 n = 2 26°30′N 83°02′W ; FSBC I 131437 n = 1 25°41′N 83°04′W ; FSBC I 131442 n = 1 25°58′N 83°04′W ; FSBC I 132649 n = 4 26°03′N 83°04′W ; FSBC I 129200 n = 1 24°49′N 83°05′W ; FSBC I 129199 n = 4 25°06′N 83°05′W ; FSBC I 072994 n = 1 26°20′N 83°05′W ; FSBC I 129195 n = 6 26°30′N 83°05′W ; FSBC I 122377 n = 2 25°20′N 83°06′W ; FSBC I 073345 n = 2 26°10′N 83°06′W ; FSBC I 102814 n = 1 26°05′N 83°07′W ; FSBC I 072995 n = 3 26°24′N 83°07′W ; FSBC I 070274 n = 2 27°37′N 83°07′W ; FSBC I 109125 n = 1 26°05′N 83°08′W ; FSBC I 132652 n = 1 27°09′N 83°08′W ; FSBC I 102824 n = 1 24°48′N 83°09′W ; FSBC I 109132 n = 1 25°04′N 83°09′W ; FSBC I 106536 n = 2 26°30′N 83°09′W ; FSBC I 072992 n = 1 26°31′N 83°09′W ; FSBC I 082086 n = 1 27°23′N 83°09′W ; FSBC I 129196 n = 1 26°12′N 83°10′W ; FSBC I 122381 n = 2 26°56′N 83°10′W ; FSBC I 132643 n = 3 26°27′N 83°11′W ; FSBC I 115744 n = 1 25°05′N 83°12′W ; FSBC I 082056 n = 2 26°52′N 83°12′W ; FSBC I 109162 n = 1 25°19′N 83°13′W ; FSBC I 135103 n = 1 25°37′N 83°13′W ; FSBC I 102475 n = 2 26°24′N 83°13′W ; FSBC I 122379 n = 2 26°29′N 83°13′W ; FSBC I 092410 n = 2 26°48′N 83°13′W ; FSBC I 122380 n = 1 26°53′N 83°13′W ; FSBC I 077271 n = 1 27°03′N 83°14′W ; FSBC I 129197 n = 1 26°04′N 83°15′W ; FSBC I 075746 n = 1 27°21′N 83°15′W ; FSBC I 102474 n = 1 27°29′N 83°15′W ; FSBC I 135104 n = 1 25°39′N 83°16′W ; FSBC I 131443 n = 1 26°23′N 83°16′W ; FSBC I 131439 n = 1 26°31′N 83°16′W ; FSBC I 082074 n = 1, FSBC I 128070 n = 2 27°30′N 83°16′W ; UF 018039 n = 5 26°24′N 83°17′W ; FSBC I 109163 n = 1 26°25′N 83°17′W ; FSBC I 131423 n = 4 27°18′N 83°17′W ; FSBC I 131434 n = 1 25°09′N 83°18′W ; FSBC I 072983 n = 1 25°53′N 83°18′W ; FSBC I 131438 n = 3 26°21′N 83°18′W ; FSBC I 102823 n = 1 27°50′N 83°18′W ; FSBC I 132642 n = 1 26°35′N 83°19′W ; FSBC I 132654 n = 2 27°49′N 83°19′W ; FSBC I 131424 n = 1 27°05′N 83°21′W ; FSBC I 070266 n = 1, FSBC I 070269 n = 1, FSBC I 070295 n = 1, FSBC I 070307 n = 1, FSBC I 070310 n = 1, FSBC I 070330 n = 1, FSBC I 070336 n = 1, FSBC I 070427 n = 1, FSBC I 070449 n = 1, FSBC I 071378 n = 1, FSBC I 071404 n = 1, FSBC I 071405 n = 3, FSBC I 071411 n = 2, FSBC I 117246 n = 2, FSBC I 117260 n = 1, FSBC I 117261 n = 1, FSBC I 117264 n = 5, FSBC I 117267 n = 3 26°24′N 83°22′W ; FSBC I 075414 n = 2(2) 27°21′N 83°22′W ; FSBC I 128069 n = 1 27°25′N 83°22′W ; FSBC I 117237 n = 3 27°38′N 83°22′W ; FSBC I 132645 n = 1 26°08′N 83°23′W ; FSBC I 131440 n = 1 27°47′N 83°25′W ; FSBC I 131429 n = 1 24°45′N 83°26′W ; FSBC I 074814 n = 1 27°13′N 83°26′W ; FSBC I 014301 n = 1 27°18′N 83°27′W ; FSBC I 069561 n = 5 27°46′N 83°27′W ; FSBC I 129202 n = 1 27°50′N 83°27′W ; FSBC I 132644 n = 1 26°14′N 83°28′W ; FSBC I 004494 n = 2, FSBC I 070265 n = 1, FSBC I 070276 n = 16, FSBC I 070287 n = 47, FSBC I 070298 n = 1, FSBC I 070302 n = 1, FSBC I 070308 n = 2, FSBC I 070328 n = 3, FSBC I 070337 n = 1, FSBC I 070339 n = 1, FSBC I 070340 n = 1, FSBC I 070436 n = 1, FSBC I 070437 n = 3, FSBC I 070443 n = 14, FSBC I 070454 n = 4, FSBC I 070455 n = 1, FSBC I 070463 n = 12, FSBC I 070464 n = 5, FSBC I 070465 n = 3(1), FSBC I 070484 n = 6, FSBC I 070485 n = 1, FSBC I 071388 n = 2, FSBC I 071390 n = 2, FSBC I 071396 n = 4, FSBC I 071406 n = 18, FSBC I 071409 n = 7, FSBC I 071410 n = 2, FSBC I 071412 n = 1, FSBC I 071424 n = 7(1), FSBC I 077286 n = 4(2), FSBC I 117242 n = 5, FSBC I 117243 n = 2, FSBC I 117247 n = 2, FSBC I 117248 n = 1, FSBC I 117254 n = 1, FSBC I 117258 n = 4, FSBC I 117270 n = 5 27°37′N 83°28′W ; FSBC I 132653 n = 2 27°22′N 83°29′W ; FSBC I 109167 n = 2 27°49′N 83°29′W ; UF 010796 n = 1 26°29′N 83°30′W ; FSBC I 129193 n = 6 27°58′N 83°30′W ; FSBC I 091944 n = 3 26°59′N 83°31′W ; FSBC I 072985 n = 5 27°47′N 83°31′W ; FSBC I 109142 n = 1 27°38′N 83°32′W ; FSBC I 129194 n = 5 27°58′N 83°32′W ; FSBC I 131441 n = 1 27°49′N 83°33′W ; FSBC I 082070 n = 5 27°32′N 83°35′W ; FSBC I 069415 n = 2 27°53′N 83°35′W ; FSBC I 115743 n = 1 27°04′N 83°36′W ; FSBC I 068105 n = 2 28°05′N 83°37′W ; FSBC I 102816 n = 1 28°28′N 83°37′W ; FSBC I 082016 n = 1 28°02′N 83°38′W ; FSBC I 132641 n = 1 27°07′N 83°39′W ; UF 007933 n = 1 27°08′N 83°40′W ; FSBC I 128074 n = 2 28°05′N 83°40′W ; FSBC I 082018 n = 1 28°32′N 83°40′W ; FSBC I 082017 n = 1 27°21′N 83°42′W ; FSBC I 122372 n = 2 27°03′N 83°43′W ; FSBC I 077107 n = 1 27°26′N 83°43′W ; FSBC I 074817 n = 2 27°24′N 83°45′W ; FSBC I 131425 n = 1 25°40′N 83°46′W ; FSBC I 072996 n = 2 28°10′N 83°47′W ; FSBC I 082065 n = 1 28°03′N 83°48′W ; FSBC I 069554 n = 1, FSBC I 117240 n = 1 27°13′N 83°49′W ; FSBC I 072988 n = 1 28°09′N 83°49′W ; FSBC I 074818 n = 2, FSBC I 074820 n = 1 27°43′N 83°50′W ; FSBC I 082055 n = 2 27°25′N 83°51′W ; FSBC I 074821 n = 1 27°31′N 83°51′W ; FSBC I 068100 n = 3 28°03′N 83°51′W ; FSBC I 122370 n = 2 27°47′N 83°56′W ; FSBC I 122371 n = 3 27°42′N 83°57′W ; FSBC I 005760 n = 1, FSBC I 005765 n = 1, FSBC I 070267 n = 1, FSBC I 070272 n = 2, FSBC I 070277 n = 3, FSBC I 070278 n = 2, FSBC I 070289 n = 1, FSBC I 070301 n = 1, FSBC I 070305 n = 1, FSBC I 070332 n = 2, FSBC I 070428 n = 1, FSBC I 070429 n = 1, FSBC I 070433 n = 1(1), FSBC I 070435 n = 3, FSBC I 070438 n = 1, FSBC I 070440 n = 2, FSBC I 070452 n = 1, FSBC I 071386 n = 3, FSBC I 071389 n = 1, FSBC I 071394 n = 2, FSBC I 071402 n = 1, FSBC I 077267 n = 1, FSBC I 077270 n = 1, FSBC I 117249 n = 1, FSBC I 117274 n = 3 27°37′N 83°58′W ; FSBC I 072987 n = 1 28°05′N 83°60′W ; FSBC I 072999 n = 3 28°39′N 84°00′W ; FSBC I 122369 n = 1 28°11′N 84°01′W ; FSBC I 082062 n = 7 28°26′N 84°03′W ; FSBC I 109164 n = 1 27°16′N 84°04′W ; FSBC I 132640 n = 5 27°46′N 84°05′W ; FSBC I 074822 n = 3 28°28′N 84°05′W ; FSBC I 129201 n = 1 29°27′N 84°05′W ; FSBC I 132639 n = 2 28°37′N 84°10′W ; FSBC I 068172 n = 1 29°10′N 84°10′W ; FSBC I 102819 n = 1(1) 28°40′N 84°11′W ; FSBC I 102815 n = 3 28°46′N 84°12′W ; FSBC I 071387 n = 1, FSBC I 077269 n = 1 27°37′N 84°13′W ; FSBC I 074816 n = 1 28°40′N 84°13′W ; FSBC I 131422 n = 1 27°37′N 84°15′W ; FSBC I 122368 n = 1 28°25′N 84°15′W ; FSBC I 069563 n = 2 28°26′N 84°15′W ; FSBC I 082114 n = 1 28°32′N 84°17′W ; FSBC I 072989 n = 1 29°20′N 84°17′W ; FSBC I 068051 n = 2 28°09′N 84°19′W ; FSBC I 109124 n = 1, FSBC I 109138 n = 2 28°14′N 84°20′W ; FSBC I 131421 n = 1 28°21′N 84°21′W ; FSBC I 122367 n = 1 28°22′N 84°21′W ; FSBC I 109148 n = 1 28°24′N 84°24′W ; FSBC I 074813 n = 1 28°27′N 84°26′W ; FSBC I 122366 n = 1 28°32′N 84°29′W ; FSBC I 082014 n = 1 28°54′N 84°29′W ; FSBC I 132638 n = 1 28°33′N 84°32′W ; FSBC I 069560 n = 1 29°31′N 84°33′W ; FSBC I 122365 n = 1 28°46′N 84°35′W ; FSBC I 131420 n = 1 29°07′N 84°35′W ; FSBC I 109170 n = 1 28°54′N 84°38′W ; FSBC I 082059 n = 2 28°59′N 84°43′W ; FSBC I 082071 n = 5 28°57′N 84°48′W ; FSBC I 127994 n = 1 29°01′N 84°54′W ; FSBC I 122363 n = 1 29°08′N 84°54′W ; FSBC I 109145 n = 1 29°05′N 84°58′W ; FSBC I 132637 n = 1 29°33′N 85°48′W ; FSBC I 109149 n = 1 29°27′N 85°53′W ; FSBC I 109166 n = 1 29°31′N 85°53′W ; FSBC I 069558 n = 1(1) 30°02′N 86°23′W ; USNM E38378 n = 1(1) GPS n/a. Gulf of Mexico (West of De Soto Canyon)— FSBC I 069562 n = 1 29°44′N 87°48′W ; FSBC I 068047 n = 1 29°40′N 87°57′W ; USNM E23177 n = 1 29°15′N 88°37′W ; UF 011688 n = 5 28°20′N 90°43′W ; USNM E45681 n = 20(1) 28°59′N 92°16′W ; FSBC I 070426 n = 1, FSBC I 070479 n = 1, FSBC I 070666 n = 201, FSBC I 073344 n = 1(1), USNM E6795 n = 113(1), USNM E8854 n = 3(1) GPS n/a

.

Etymology. The specific epithet is dedicated to the memory of Larry McEdward, Ph.D. (the larval marvel), mentor and scientist whose passion and dedication to the study of starfish, larval biology and ecology, life history evolution, and computing technologies in biology inspired a new generation of scientists.

External morphology. Unless otherwise stated, the following description is based on the holotype and paratypes.

Five short arms, each wide at the disk and tapering sharply to a pointed tip ( Figs. 1A, 1B ). The largest of the type series (holotype USNM 1551002) with R = 27.1 mm, r = 8.9 mm, R:r = 3.0, 16 SM plates, and R:SM# = 1.7. The IM plates do not project conspicuously beyond the SM plates. At the interradial arcs, the SM plates are laterally flush, and the IM plates form a sheer, well-defined lateral edge. The madreporite is hemispherical with smooth, parallel gyri. The ocular plates are about equal in size to adjacent SM plates and have a number of small spines. No pedicellaria were observed on specimens of the type series.

The paxillar area is flush with or only slightly lower than the top of the SM plates, giving the abactinal surface a flat appearance except for the projecting anal cone, which is usually conspicuous. Each paxilla has 6–9 peripheral spinelets surrounding 1 or 2 central spinelets ( Fig. 1C ). Spinelets may articulate vertically around the central spinelets, as in the holotype, or divergently around the central spinelets, as in the paratypes. The paxillar spinelets are slender, rod-shaped, and rugose. The shape and thickness of the paxillar spinelets do not change conspicuously from disk to arm tip. The paxillar area is wide at the base of the arms, with the paxillar columns distributed in discrete transverse rows. Paxillae are not dense and are easily distinguished from adjacent paxillae ( Fig. 1D ).

The SM plates are small, similar in length and width, and covered by rod-shaped rugose spinelets. Spinelets near the center of the plate are thicker than peripheral spinelets. This is most conspicuous on the SM plates at the interradius. SM plates are tumid (distinctly rounded on the upper surface) and separated by moderately wide fascioles. All specimens of the type series have a large articulating spine on the adradial edge of the abactinal surface of SM plates of the interradius ( Fig. 1D ). Small, inconspicuous spines are sometimes present on the abradial edge of the abactinal surface of other SM plates. Presence and abundance of spines on the SM plates are variable.

The IM plates usually have two ambital fringe spines ( Fig. 1E ). These spines are moderately compressed to slightly rounded and are usually erect at the interradial arc and appressed distally. The fringe spines are about equal in length, or the distal spine is slightly longer. Below and adjacent to the ambital fringe spines are 1 or 2 shorter, acute spines, similar in length to the spines along the distal edge of the IM plate’s actinal surface. The actinal surface of the IM plates is typically bare, with the exception of one or two tubercles, and lacks squamules (short, flat, scalelike spines).

Adambulacral plates possess two discrete rows of compressed and acute or blunt spines ( Fig. 1F ). The first adambulacral row (furrow spines) has a long middle spine perpendicular to the ambulacral groove and shorter, proximal and distal spines. The second row (first subambulacral row) of spines is composed of 3 flat, acute spines, the middle one of which is wider and longer than the proximal and distal spines. This middle spine is usually longer than the middle spine of the first row, while the proximal and distal spines of the second adambulacral row are about the same length as the proximal and distal spines of the first row. Variation: a third row of adambulacral spines may be present on some (usually very few) plates. This row may have 1 or 2 acicular (rod-shaped; round in cross section) spinelets that are much shorter than all the other spines on the same plate.

Ten actinal intermediate plates are present in each interradial area and are covered with short, acicular spinelets. A longer, wider, acute spine may be present in the center of each actinal intermediate plate.

The smaller specimens of the type series (paratypes: FSBC I 122373 b, R = 13.0 mm, r = 3.8 mm 13 SM plates; FSBC I 122373 c R = 11.9 mm, r = 4.0 mm, 12 SM plates) concur with the features described above with only a few noticeable (probably size-related) differences in the number of spines and plates. Smaller specimens, for example, occasionally have 1 fringe spine on some IM plates instead of 2. Fewer paxillar spinelets are also observed on smaller specimens. The number of actinal intermediate plates varies between individuals but typically ranges from 4–12 plates per area.

Color. Living specimens are pale pink, pale orange, or nearly white on the abactinal surface ( Fig. 2 ). The arm tips are pale purple (white if abraded). The paxillar area is marked by a dark, midradial, longitudinal line from the tip of the arm to the disk, forming a faint pentagon around the anal cone. SM spines may be the same color as the surface of the plate or white. SM spines may possess a faint orange band at the base of the spine. The fringe spines are white and may have a faint orange band at the base. The actinal surface is white.

Figures

FIGURE 1. Astropecten mcedwardi n. sp. A–B, USNM 1551002, holotype (below, largest), USNM 1551004, paratype (upper left) and USNM 1551005, paratype (upper right).A, Abactinal surface. B, Actinal surfaces. C–D, USNM 1551005. Rugose paxillar spinelets (C) and the abactinal surface (D) showing the madreporite (arrow) and large spine on interradial superomarginal plate, paxillar area at the base of an arm, and one interradial superomarginal spine. E–F, USNM 1551002. Actinal surface of the inferomarginal plates (E) and the adambulacral plates (F). Scale bars: A–B, 1 cm; C, 0.2 mm; D, 0.5 mm; E–F, 1 mm.

FIGURE 2. Astropecten mcedwardi color variations. A, USNM 1551002, holotype (left, largest), USNM 1551004, paratype (upper right) and USNM 1551005, paratype (lower right). B, FSBC I 122364, paratype. C, FSBC I 131421, paratype. D, FSBC I 131433, paratype. E–G, FSBC I 131436, paratypes. Scale: 1 cm. Photographs: FWC Fisheries Independent Monitoring staff (A–B), Robert Lasley (C), and Janessa Cobb (D–G).

FIGURE 5. Comparison of Astropecten spp. body shapes where R = 24.3–25.7 mm.A, A. mcedwardi FSBC I 117245, paratype (R:r 2.9, R:SM# 1.6). B, A. duplicatus FSBC I 70285 (R:r 3.4, R:SM# 1.6). C, A. articulatus FSBC I 125180 (R:r 3.5, R:SM# 1.0). D, A. antillensis ZMUC AST-4-23, syntype (R:r 4.4, R:SM# 1.2). E, A. marginatus USNM E18385 (R:r 3.5, R:SM# 0.9). F, A. karankawai FSBC I 134511 (R:r 3.8, R:SM# 1.5). Scale bar 1 cm.

FIGURE 6. Inferomarginal plates with fringe spines (left: distal, right: proximal). A, A. mcedwardi FSBC I 005769 (R = 17 mm). B, A. duplicatus FSBC I 070291 (R = 19). C, A. articulatus FSBC I 125180 (R = 24). D, A. antillensis ZMUC AST-4-22, syntype (R = 29). E, A. marginatus USNM E18385 (R = 22mm). F, A. karankawai USNM E22502, paratype (R = 21mm). Scale bar 0.5 cm.

FIGURE 8. Adambulacral plates and spines (left: proximal, right: distal) of Astropecten spp. A, A. mcedwardi FSBC I 005769 (R = 17 mm). B, A. duplicatus FSBC I 70291 (R = 19 mm). C, A. articulatus FSBC I 125180 (R = 24) with arrows identifying spines offset behind the proximal and slightly enlarged distal spines of the second row. D, A. antillensis ZMUC AST-4-22, syntype (R = 29 mm). E, A. marginatus USNM E18385 (R = 19 mm). F, A. karankawai USNM E22502, paratype (R = 21 mm). Scale bar 0.5 cm.

FIGURE 9. Spination of superomarginal plates along the arms of Astropecten spp. A, A. antillensis ZMUC AST-4-23, syntype (R = 25 mm). B, A. mcedwardi FSBC I 117245, paratype (R = 21 mm). C, A. duplicatus FSBC I 70283 (R = 26 mm). Scale bar 0.5 cm.