KEY TO THE FAMILIES OF OCTOCORALLIA

Couplet Number	Description	Go To:
1A	Rigid skeleton of pure crystalline aragonite (Helioporacea)	2
1B	Skeletal components absent or if present then composed predominantly of calcite and/or gorgonin	3
2A	Massive skeleton formed of fused corallites, powder blue in color. Sclerites absent	HELIOPORIDAE
2B	Polyps retractile within rigid cylindrical calyces of nonspicular crystalline aragonite. Polyps with calcitic sclerites	LITHOTELESTIDAE
3A	Colonies with a basal muscular peduncle for anchoring in soft substrata. Polyps trimorphic or quadrimorphic; oozooid present (Pennatulacea)	4
3B	Colonies without a basal peduncle. Polyps monomorphic or dimorphic, oozooid absent (Alcyonacea)	18
4A	Adjacent polyps free, not fused to any degree	5
4B	Proximal portions of adjacent autozooids fused to some degree, forming polyp leaves or raised ridges, or joined only at the bases	15
5A	Colonies cordate/foliate; rachis greatly flattened, lying on surface of substratum	RENILLIDAE
5B	Colonies cylindrical, capitate, clavate, or elongate; rachis erect, not lying on substratum	6
6A	Autozooids distributed evenly on all sides of rachis, or proximal portion of rachis with a single longitudinal furrow or V-shaped region devoid of polyps	7
6B	Autozooids confined to a terminal cluster, or arranged biserially along rachis, or in whorls of two to four arranged sparsely along rachis, or arranged on three sides of rachis with a naked dorsal tract along entire length of rachis	8
7A	Siphonozooids without calyces	VERETILLIDAE
7B	Siphonozooids with conspicuously bifurcated, spiculated calyces	ECHINOPTILIDAE
8A	Autozooids arranged in a terminal cluster at the end of a long slender stalk	UMBELLULIDAE
8B	Autozooids arranged along the sides of the rachis	9
9A	Colonies cylindrical or clavate with distal portion somewhat wider than rest of colony. Polyps arranged biserially and individually (not in oblique rows), or disposed on three sides of rachis with a naked dorsal tract along the entire length of the rachis	KOPHOBELEMNIDAE
9B	Colonies elongated and narrow with uniform thickness, or if clavate then polyps arranged in oblique rows. Polyps arranged biserially or in isolated pairs or whorls	10
10A	Colonies without sclerites. Polyps arranged biserially without calyces	ANTHOPTILIDAE
10B	Colonies with or without sclerites, and polyps arranged in pairs or whorls of 2-4, without calyces	11
11A	Rachis with or without sclerites Polyps arranged in pairs or whorls of 2-4, without calyces	12
11B	Rachis with sclerites. Polyps arranged biserially, with calyces	13
12A	Rachis with spindles or rods (<0.10 mm)	SCLEROPTILIDAE
12B	Rachis without sclerites or with minute irregularly-shaped rods (>0.05 mm)	CHUNELLIDAE
13A	Autozooids tubular with calyces having eight conspicuous terminal teeth; siphonozooids and autozooids morphologically similar	FUNICULINIDAE
13B	Calyces with zero to eight terminal teeth. Siphonozooids and autozoods very different morphologically	14
14A	Polyps arranged in oblique or transverse rows along the rachis. Colonies often somewhat clavate	STACHYPTILIDAE
14B	Autozooids arranged in one to three longitudinal rows along the rachis; colonies elongate, not clavate	PROTOPTILIDAE
15A	Autozooids disposed on raised ridges or pads that are obliquely arranged along the rachis	16
15B	Autozooids disposed on conspicuous polyp leaves that emanate laterally along the rachis in two opposite longitudinal series	17
16A	Rachis with sclerites. Polyps with bifurcated, spiculiferous calyces	HALIPTERIDAE
16B	Rachis without sclerites. Polyps without calyces	ANTHOPTILIDAE
17A	Polyp leaf sclerites reduced (ovals and plates) or absent. Siphonozooids few and sparsely distributed	VIRGULARIIDAE
17B	Polyp leaf sclerites are numerous and conspicuous (spindles and needles). Siphonozooids numerous to congested and densely-set	PENNATULIDAE
18A	Permanently solitary octocorals composed of a single large polyp	TAIAROIDAE
18B	Colonial octocorals; polyps multiple, produced by vegetative budding	19
19A	Polyps separate, joined only at the proximal bases by stolons or multilayered platforms	20
19B	Polyps partly united laterally or contained in a common coenenchyme	23
20A	Calcareous skeleton absent	CORNULARIIDAE
20B	Calcareous skeletal elements present	21
21A	Colonies with stolons forming rigid multi-layered platforms above the substratum	TUBIPORIDAE
21B	Colonies arborescent with a reduced stolon, or colonies with conspicuous stolons not forming rigid multi-layered platforms	22
22A	Colonial growth form richly arborescent. Polyps non-retractile, calyces absent	COELOGORGIIDAE
22B	Colonies composed of retractile polyps with cylindrical, conical, or mound-like calyces	CLAVULARIIDAE
23A	Colonies composed of one elongated axial polyp with many short lateral polyps (autozooids) embedded in the thick coenenchyme of the axial polyp wall	PSEUDOGORGIIDAE
23B	Single dominant axial polyp lacking; smaller polyps in dimorphic taxa are siphonozooids, not autozooids	24
24A	Coenenchyme not differentiated into outer and inner layers. Gastric cavities of polyps extend throughout height of colony	25
24B	Coenenchyme differentiated into outer and inner layers (cortex and medulla), or internal calcareous and/or proteinaceous axis present	29
25A	Sclerites composed of anhedral rods or nodules	XENIIDAE
25B	Sclerites of composed of subhedral or euhedral crystals	26
26A	Polyparium composed of branches or clusters of polyps, which is retractile into a common basal stalk or trunk	PARALCYONIIDAE
26B	Polyparium, if composed of branches or clusters of polyps, not retractile into common basal stalk or trunk. If polyparium is retractile, then not composed of branches or clusters of polyps	27
27A	Polyps often grouped in clusters or restricted to branch tips of the polypary	NEPHTHEIDAE
27B	Polyps evenly distributed on the surface of the polypary	28
28A	Colonies with a rigid consistency, outer surface rough, containing large tuberculate sclerites, longitudinally placed. Polyps retractile into mostly prominent calyces	NIDALIIDAE
28B	Colonies usually fleshy, sclerites generally not in the form of longitudinally disposed large spindles. Calyces absent except in a few species	ALCYONIIDAE
29A	Coenenchyme differentiated into an outer cortex and an inner medulla. Medulla composed entirely of free but densely set sclerites	30
29B	Colony with axial support composed of inseparably fused sclerites, or sclerites united by horny proteinaceous material (gorgonin) and/or CaCO3, or entirely proteinaceous and permeated by varying amounts of non-spicular CaCO3, or totally calcified without sclerites or horn	33
30A	Colonies dimorphic	PARAGORGIIDAE
30B	Colonies monomorphic	31
31A	Cortex and medulla separated by a ring of longitudinal boundary canals	32
31B	Cortex and medulla not separated by a ring of longitudinal boundary canals	BRIAREIDAE
32A	Sclerites of the medulla are mostly smooth and curved, partly fused to form a network	SUBERGORGIIDAE
32B	Sclerites of the medulla include tuberculate or somewhat branched rods or spindles	ANTHOTHELIDAE
33A	Axis jointed (segmented); with alternating nodes and internodes	34
33B	Axis not jointed; continuous and uniform, without alternating nodes and internodes	36
34A	Axis with sclerites	35
34B	Axis without sclerites	ISIDIDAE
35A	Branches arise from proteinaceous nodes	MELITHAEIDAE
35B	Branches arise from calcareous internodes	PARISIDIDAE
36A	Polyps dimorphic	CORALLIIDAE
36B	Polyps monomorphic	37
37A	Central axis proteinaceous with ridges and grooves, the ridges are spiny resembling the stem of a black coral or rosebush	DENDROBRACHIIDAE
37B	Central axis smooth or longitudinally grooved, but not with conspicuous spiny ridges	38
38A	Central axis with hollow, cross-chambered core (Suborder Holaxonia)	39
38B	Central axis with solid core (Suborder Calcaxonia)	42
39A	Chambered core of axis surrounded by smooth sclerites bound together by sheaths of horn-like material	KEROEIDIDAE
39B	Chambered core of axis surrounded by horn-like layers that may contain non-spicular calcareous material	40
40A	Polyps non-retractile. Polyps covered in spindles that often forming chevrons	ACANTHOGORGIIDAE
40B	Polyps retractile. Polyps without sclerites that form chevrons	41
41A	Polyps usually with sclerites comprising some form of crown and points. Sclerites >0.3 mm in length	PLEXAURIDAE
41B	Polyps without sclerites or with small rodlike bodies. Sclerites <0.3 mm in length	GORGONIIDAE
42A	Sclerites include many double heads	ELLISELLIDAE
42B	No double heads are present	43
43A	Colonies zooxanthellate, in shallow water (<50 m). Sclerites are irregularly shaped ovals, rodlets, and crosses (<0.1 mm in length)	IFALUKELLIDAE
43B	Colonies azooxanthellate, in deeper water (mostly >50 m). Sclerites are mostly derived from scales (>0.1 mm in length)	44
44A	Surface of axis longitudinally grooved, usually gray to black, sometimes with a metallic luster	PRIMNOIDAE
44B	Surface of axis smooth, not grooved, with a metallic luster of greenish, bronze, or gold	CHRYSOGORGIIDAE

ORDER HELIOPORACEA	2 FAMILIES
ORDER PENNATULACEA	14 FAMILIES
ORDER ALCYONACEA	30 FAMILIES
TOTAL	46 FAMILIES OF OCTOCORALS

ILLUSTRATED KEY TO THE FAMILIES OF OCTOCORALLIA

by

Gary C. Williams

California Academy of Sciences

ORDER HELIOPORACEA 2 FAMILIES ORDER PENNATULACEA 14 FAMILIES ORDERALCYONACEA 30 FAMILIES TOTAL 46 FAMILIES OF OCTOCORALS

ORDER HELIOPORACEA

2 FAMILIES

ORDER PENNATULACEA

14 FAMILIES

ORDERALCYONACEA

30 FAMILIES

TOTAL

46 FAMILIES OF OCTOCORALS

Couplet Number

Description

Go To:

1A

Rigid skeleton of pure crystalline aragonite (Helioporacea)

2

1B

Skeletal components absent or if present then composed predominantly of calcite and/or gorgonin

3

2A

Massive skeleton formed of fused corallites, powder blue in color. Sclerites absent

2B

Polyps retractile within rigid cylindrical calyces of nonspicular crystalline aragonite. Polyps with calcitic sclerites

3A

Colonies with a basal muscular peduncle for anchoring in soft substrata. Polyps trimorphic or quadrimorphic; oozooid present (Pennatulacea)

4

3B

Colonies without a basal peduncle. Polyps monomorphic or dimorphic, oozooid absent (Alcyonacea)

18

4A

Adjacent polyps free, not fused to any degree

5

4B

Proximal portions of adjacent autozooids fused to some degree, forming polyp leaves or raised ridges, or joined only at the bases

15

5A

Colonies cordate/foliate; rachis greatly flattened, lying on surface of substratum

5B

Colonies cylindrical, capitate, clavate, or elongate; rachis erect, not lying on substratum

6

6A

Autozooids distributed evenly on all sides of rachis, or proximal portion of rachis with a single longitudinal furrow or V-shaped region devoid of polyps

7

6B

Autozooids confined to a terminal cluster, or arranged biserially along rachis, or in whorls of two to four arranged sparsely along rachis, or arranged on three sides of rachis with a naked dorsal tract along entire length of rachis

8

7A

Siphonozooids without calyces

7B

Siphonozooids with conspicuously bifurcated, spiculated calyces

8A

Autozooids arranged in a terminal cluster at the end of a long slender stalk

8B

Autozooids arranged along the sides of the rachis

9

9A

Colonies cylindrical or clavate with distal portion somewhat wider than rest of colony. Polyps arranged biserially and individually (not in oblique rows), or disposed on three sides of rachis with a naked dorsal tract along the entire length of the rachis

9B

Colonies elongated and narrow with uniform thickness, or if clavate then polyps arranged in oblique rows. Polyps arranged biserially or in isolated pairs or whorls

10

10A

Colonies without sclerites. Polyps arranged biserially without calyces

10B

Colonies with or without sclerites, and polyps arranged in pairs or whorls of 2-4, without calyces

11

11A

Rachis with or without sclerites Polyps arranged in pairs or whorls of 2-4, without calyces

12

11B

Rachis with sclerites. Polyps arranged biserially, with calyces

13

12A

Rachis with spindles or rods (<0.10 mm)

12B

Rachis without sclerites or with minute irregularly-shaped rods (>0.05 mm)

13A

Autozooids tubular with calyces having eight conspicuous terminal teeth; siphonozooids and autozooids morphologically similar

ORDER HELIOPORACEA

2 FAMILIES

ORDER PENNATULACEA

14 FAMILIES

ORDER
ALCYONACEA

30 FAMILIES

TOTAL

46 FAMILIES OF OCTOCORALS

ORDER
ALCYONACEA