A revision of the genus Saccoglossus (Hemichordata: Enteropneusta: Harrimaniidae) with taxonomic descriptions of five new species from the Eastern Pacific Author C. B. Cameron Author C. Deland Author T. H. Bullock text Zootaxa 2010 2010-05-25 2483 1 22 journal article 32068 10.5281/zenodo.893894 2bb49143-5cbd-42f7-9689-de741f351ff7 1175-5326 893894 Saccoglossus sonorensis n. sp. ( Figs 1G, H ; 5A–G) Material examined. A single specimen in good condition which will be the type (T.H.B. accession no. 409) was collected from Cholla Bay, near Puerto Penasco, Sonora , Mexico ( 31° 17' N , 113° 35 W) in the Gulf of California , by T.H.B. in January, 1949, in slightly muddy sand. Three more anterior fragments were taken in January, 1957, at the same place and a dozen more in 1971. When an area with typical castings every few meters was found, nearly every casting yielding at least a tail fragment the habit similar to that of S. pusillus , S. kowalevskii , S. bromophenolosus and perhaps typical for the genus. Holotype : Accession no. NMNH 1132799. Paratype : Accession no. NMNH 1132800. External features ( Figure 1 G, H ): The total length is commonly 120-150 mm or more, the proboscis is 25 mm long, the collar is 2-4 mm . The proboscis is 2-3 mm wide and yellow orange; the collar is only slightly wider and a little deeper orange. Genital ridges are not conspicuous but the gonads commence immediately behind the collar. Ventral muscular ridges in the trunk are not present. Internal features ( Figure 5 ): The proboscis nerve fiber layer is rather thin, but shows a slight middorsal thickening. The circular muscle fiber layer is only about 4 fibers thick. Longitudinal muscle fibers are arranged in 5 to 6 concentric rings ( Fig. 5A ). The proboscis lumen extends as a narrow round space almost to the tip of the proboscis, the anterior most part being occupied by connective tissue cells. It is lined by a layer of amoeboid cells in turn surrounded by a thin layer of circular fibers ( Fig. 5A inset). The glomerulus extends anteriorly a little over the tip of the stomochord. The tip of the cardiac vesicle, which extends slightly beyond the stomochord, is surrounded on all sides by the glomerulus. The lumen of the stomochord extends to its tip only in the form of small irregular spaces, which are not continuous with each other. There is a dorsal glomerulus. The glomerulus covers even the ventral side of the stomochord, appearing in cross section as four or five finger-like processes hanging down from the ventral side of the stomochord. The cardiac vesicle is rather large and surrounds the stomochord on all sides except ventrally. But the lumen of the cardiac vesicle is quite filled with connective tissue, excepting the middorsal part ( Fig. 5A ). The stomochord lumen has two ventro lateral caeca, equally well developed and continuous with the primary central lumen ( Fig. 5B ). Posterior to these ventro lateral caeca, that is in the neck region, the wall of the stomochord becomes thinner and the stomochord now has a spacious and clear lumen. The end plate of the proboscis skeleton has a conspicuous middorsal spine which projects into the ventral caeca of the stomochord ( Fig. 5C ). The proboscis skeleton has a distinct and deep keel over a short length in its anterior part ( Fig. 5C ), but the keel is absent posterior to this, although the skeletal body is normal; the length of the keel antero-posteriorly is about 200 µm. Only the right proboscis canal is present ( Fig. 5C ), occupying a median dorsal position posterior to the cardiac vesicle, and opening by a right proboscis pore. The dorsal and ventral septa are absent. The collar epithelium is about 700 µm in thickness. There are no neuropores. The perihaemal cavities extend up to a few microns anterior to the proboscis pore. They are confluent at their anterior end. The collar nerve cord has neither a lumen nor any lacunae ( Fig. 5D ). There are three dorsal roots arising from the collar nerve cord and entering the dorsal epidermal nerve layer. A dorsal mesentery is absent and the ventral one is confined to the posterior half of the collar. The skeletal cornua extend nearly to the posterior end of the collar, but just before their posterior extremity they take a sharp turn ventral wards from their dorsolateral position. The peribuccal diverticula are absent. The collar canals are vertically oriented ( Fig. 5E , and inset). Their walls are not thick but the nuclei are arranged in several strata. The openings of the branchial sacs on either side are in pairs, that is the left and the right pore are opposite to each other and not alternating. These openings are at the bottom of a deep and narrow groove along the sublateral line on either side of the middorsal line ( Fig. 5F ). The gonads commence immediately behind the collar. They are simple, unlobed sacs which open individually onto the lateral (outer) wall of the sublateral groove. The gonads open along with the gill pouches and do not alternate with the latter. The branchial part is twice as large as the ventral part. The ventral and lateral aspects of the trunk coelom are filled with longitudinal muscle fibers but no ventro-lateral ridges are formed ( Fig. 5F ). Remarks. S. sonorensis does not resemble any known species of the genus in more than one or two of the usual specific characters. The only exception to this statement is S. otagoensis , which resembles the present species in the absence of the ventral muscular ridges in the trunk, the absence of the dorsal mesentery in the collar, the absence of the dorsal crest on the collar nerve cord and in the posterior extent of the skeletal cornua in the collar but differs in a number features such as the number of concentric muscle fiber rings in the proboscis, the external color, the side of the proboscis pore and the presence of a dorsal glomerulus. Among the species of Saccoglossus commonly occurring on the west coast of America. S. pusillus resembles the present species only in the large branchial pharynx and in the posterior extent of the cornua. Other species of the genus like S. porochordus , S. rubur , S. kowalevskii , S. shumaginensis and S. rhabdorhynchus have at the most only one character each in common with the form consideration. Thus the specimen described above does not resemble any known species sufficiently well to warrant its inclusion in that species and hence a new species has been created to receive it. In the possession of only the right proboscis pore, it appears to be unique, but this character needs confirmation from several more specimens before it could be accepted as of specific value. Etymology. The species is named after the Mexican state of Sonora . FIGURE 5. Light micrographs of transverse sections of Saccoglossus sonorensis n. sp. : A, Proboscis with heart-kidney complex. Inset: Anterior region of the proboscis coelom. B, Proboscis neck showing the skeletal spine of the proboscis skeleton. C, Proboscis neck showing the proboscis vesicle. D, Anterior region of the collar. Inset: Collar nerve cord showing a nerve root. E, Posterior region of the collar. Inset: Collar canal. F, Anterior pharyngeal region of the trunk. ac, amoeboid cells; bp, branchial pore; bv, blood vessel; cc, collar canal; cl, collar lumen; clm, collar longitudinal muscles; cv, cardiac vesicle; e, epithelia; g, glomerulus; gb, gill bar; go, gonad; nc, nerve cord; nr, nerve root; pc, proboscis coelom; phd, periheamal diverticulum; pl, pharynx lumen; plm, proboscis longitudinal muscles; pv, proboscis vesicle; s, stomochord; sc, skeletal cornua; sk, skeletal keel; sl, stomochord lumen; sp, skeletal plate; ss, skeletal spine; tlm, trunk longitudinal muscles. Scale bars A, E, F, G = 500 µm; B and F inset = 100 µm; C, D, E inset = 200 µm. TABLE 1. Comparison of external and internal characters of the species of the genus Saccoglossus . Characters from previously described species were obtained from the literature. Question marks indicate unknown character states. Three species are not included in this table: S. sulcatus ( Spengel, 1893 ) – only a figure available (no description), S. hwangtauensis ( Tchang and Koo, 1935 ) (unable to locate the paper), S. madrasensis ( Rao, 1957 ) (exists only as a conference abstract – there are no figures). S. cambrensis , S. serpentinus (Assheton, 1908) and S. ruber are synonymous species from the United Kingdom ( Burdon-Jones, 1960 ). There is little information available from the single specimen of S. ruber ( Tattersall, 1905 ) and so we used S. cambrensis (Brambell, Rogers and Goodhart, 1939 ) for our table. Species characteristics were compiled from the following references: 1. Thomas, 1956 ; 2. Thomas, 1968 ; 3. King, Giray & Kornfield, 1994 ; 4. Brambell & Goodhart, 1941 ; 5. Kapelin, 1936; 6 & 7. Horst, 1939 ; 8. Benham, 1895 ; 9. Ritter, 1902 , 1929 ; and 10. Brambell, Rogers & Cole, 1939 ; *New species. Saccoglossus apatensis 1 Saccoglossus aulakoeis 2 Saccoglossus bromophenolosus 3 continued next page Saccoglossus horsti 4 Saccoglossus inhacensis 5 Saccoglossus kowalevskii 6

Proboscis shape	tapered, long	long pear-shaped	long pointed
Proboscis length: width	longer	longer	longer
Proboscis longitudinal musculature	9-11 rings	9-10 rings	6-7 rings
Proboscis coelom	start at the tip of proboscis	?	?
Proboscis groove	dorsal	dorsal	dorsal
Proboscis pores	left	left	one
Collar length: width	as long as broad	longer than broad	longer than broad
Collar shape	annular groove at posterior end	2 posterior elevated bands separated by a groove	anterior and posterior rings
Neuropore	?	?	?
Nerve crest	?	?	?
Extent of periheamal diverticula	?	?	?
Peribuccal cavities	?	?	?
Skeleton shape	middorsal ridge	rounded tip	?
Extent of cornua	1/2 collar	1/2 collar	?
Presence and extent of parabuccal ridges	?	?	?
Presence and shape of collar canals	?	?	?
Proboscis septa	?	dorsal, ventral	?
Collar septa	?	dorsal, ventral	?
Trunk septa	?	?	?
S i z e o f b r a n c h i a l pharynx: digestive	equal	?	?
Rows of gonads	lateral	lateral	lateral
Genital ridges	yes	yes	?
Number of gill pores	30-45 pairs	12-25 pairs	60-110 pairs
Gonads start	middle of gill region	behind collar	end of gill region
Number of esophageal pores	6-8 pairs	2-5 pairs	4-8 pairs
Ventral muscular ridge	Yes	?	?

TABLE 1. (continued) Proboscis shape? tapered anteriorly? Proboscis length: width longer longer longer Proboscis longitudinal over 9 rings rings present but not well 4-5 rings musculature defined

Proboscis coelom	filled with coelomic cells	filled with granulated cells	anterior filled with cells
Proboscis groove	dorsal, ventral	?	dorsal
Proboscis pores	left	left	left
Collar length: width	longer than broad	longer than broad	equal
Collar shape	anterior and posterior thickened	posterior ring	?
Neuropore	?	anterior	?
Nerve crest	?	yes	yes
Extent of periheamal diverticula	to neck	to neck, connected anteriorly	to proboscis pore, connected anteriorly
Peribuccal cavities	?	?	yes
Skeleton shape	?	anterior median projection, rounded keel, middorsal ridge	plate flat, body narrow, keel blunt
Extent of cornua	1/2 collar	2/3 collar	1/2 collar
Presence and extent of parabuccal ridges	?	yes	?
Presence and shape of collar canals	?	horizontal, horseshoe shaped	with dorsal ridge
Proboscis septa	ventral	ventral	dorsal
Collar septa	dorsal, ventral	ventral	dorsal, ventral
Trunk septa	?	dorsal, ventral	?
S i z e o f b r a n c h i a l pharynx: digestive	?	equal	branchial larger
Rows of gonads	lateral	lateral	lateral
Genital ridges	yes	yes	yes
Number of gill pores	100-137 pairs	about 100 pairs	about 100 pairs
Gonads start	1mm after collar	1 mm after collar	few mm behind collar
Number of esophageal pores	4-8 pairs	4-6 pairs	4-6 pairs
Ventral muscular ridge	yes	yes	yes

continued next page Saccoglossus mereschkowskii 7 Saccoglossus otagoensis 8 Saccoglossus pusillus 9 TABLE 1. (continued) Proboscis shape? cylindrical, rounded at tip continued next page continued next page Material examined. One specimen (anterior end through branchial region) was dredged at a depth of 250 m offshore NNW of Coos Bay entrance, OR ( 43° 21' N , 124° 21 W) by J. McNab on August 6th 1958 . Two fragments have also been dredged at a depth of 25 meters on July 30th 1958 . Holotype: Accession no. NMNH 1132801.

Proboscis length: width	?	longer	longer
Proboscis longitudinal musculature	7-10 rings	3-4 rings	6-10 rings
Proboscis coelom	?	almost to tip of proboscis	almost to tip of proboscis, empty
Proboscis groove	dorsal	dorsal	dorsal
Proboscis pores	left	left	left
Collar length: width	equal	equal	longer than broad
Collar shape	?	2 circular grooves	posterior rim
Neuropore	?	maybe posterior	?
Nerve crest	yes	no	yes
Extent of periheamal diverticula	to proboscis pore, connected anteriorly	to proboscis pore, connected anteriorly	to stomochord opening, connected anteriorly
Peribuccal cavities	no	no	no
Skeleton shape	plate with dorso-median spine	long projecting spine, small keel	small plate and keel
Extent of cornua	?	posterior collar	posterior collar
Presence and extent of parabuccal ridges	?	yes	?
Presence and shape of collar canals	with dorsal fold	oblique, no fold	present
Proboscis septa	ventral	ventral	ventral
Collar septa	dorsal, ventral	no	dorsal, ventral
Trunk septa	?	dorsal, ventral	dorsal, ventral
S i z e o f b r a n c h i a l pharynx: digestive	branchial larger	equal	branchial larger
Rows of gonads	lateral	lateral	lateral
Genital ridges	yes only in females	yes	yes
Number of gill pores	up to 50 pairs	about 10 pairs	about 60 pairs
Gonads start	behind collar	behind collar	not reaching collar
Number of esophageal pores	?	1 pair	1 pair
Ventral muscular ridge	?	no	yes

TABLE 1. (continued)

Saccoglossus ruber ( cambrensis )10	Saccoglossus porochordus *	Saccoglossus sonorensis *
Proboscis shape	?	round in cross section	elongate
Proboscis length: width	longer	longer	longer
Proboscis longitudinal musculature	4-6 rings	8-10 rings	5-6 rings
Proboscis coelom	almost to tip of proboscis	almost to tip of proboscis, lined by connective tissue	to tip of proboscis, anterior filled with connective tissue
Proboscis groove	dorsal	dorsal	dorsal
Proboscis pores	left	left	right
Collar length: width	longer than broad	slightly longer than broad	slightly broader than long
Collar shape	anterior and posterior thickened, posterior groove	posterior ring	?
Neuropore	anterior	no	no
Nerve crest	yes	yes	no
Extent of periheamal diverticula	into neck, connected anteriorly	into neck, connected anteriorly	anterior to proboscis pore, connected anteriorly
Peribuccal cavities	no	yes	no
Skeleton shape	plate cup shaped, large keel	middorsal spine, deep keel	middorsal spine, deep keel
Extent of cornua	1/2 collar	posterior collar	posterior collar
Presence and extent of parabuccal ridges	no	no	no
Presence and shape of collar canals	horizontal, thick	vertical	vertical
Proboscis septa	ventral	no	ventral
Collar septa	dorsal, ventral	dorsal, ventral	ventral
Trunk septa	dorsal, ventral	no	no
Size of branchial pharynx: digestive	branchial larger	equal or branchial slightly larger	branchial twice larger
Rows of gonads	lateral	lateral	lateral
Genital ridges	no	yes	no
Number of gill pores	60-90 pairs	?	?
Gonads start	mid branchial region	1-1.5 mm behind collar	behind collar
Number of esophageal pores	8-12 pairs	?	?
Ventral muscular ridge	no	no	no

TABLE 1. (continued)

S a c c o g l o ss u s shumaginensis *	Saccoglossus rhabdorhynchus *	Saccoglossus palmeri *
Proboscis shape	elongate	?	long and conical
Proboscis length: width	longer	longer	longer
Proboscis longitudinal musculature	8 rings	8-9 rings	6 rings
Proboscis coelom	to tip of proboscis, anterior filled with connective tissue	almost to tip of proboscis, anterior filled with connective tissue	almost to tip of proboscis
Proboscis groove	dorsal	dorsal	dorsal
Proboscis pores	left	left	left
Collar length: width	broader than long	broader than long	?
Collar shape	two posterior rings	two posterior annular thickenings	?
Neuropore	no	anterior and posterior	anterior maybe present
Nerve crest	no	no	?
Extent of periheamal diverticula	i n to n e c k, c o n n e c te d anteriorly	to proboscis pore, seperate	?
Peribuccal cavities	yes	no	present
Skeleton shape	keel not sharp	middorsal spine	keel obtuse and short
Extent of cornua	behind middle of collar	posterior collar	?
Presence and extent of parabuccal ridges	no	no	no
Presence and shape of collar canals	horizontal	vertical	?
Proboscis septa	dorsal	ventral	dorsal, ventral
Collar septa	ventral	dorsal, ventral	dorsal
Trunk septa	no	dorsal	?
S i z e o f b r a n c h i a l pharynx: digestive	equal or branchial slightly larger	branchial larger	branchial equal or larger
Rows of gonads	lateral	lateral	lateral
Genital ridges	yes	yes	?
Number of gill pores	30-40	?	?
Gonads start	behind tenth gill pore	behind collar	?
Number of esophageal pores	6-7	?	?
Ventral muscular ridge	yes	no	?
Saccoglossus palmeri (Fig 6A–E)	n. sp.

FIGURE 6. Light micrographs of transverse sections of Saccoglossus palmeri n. sp. : A, Anterior region of the proboscis. B, Proboscis with heart-kidney complex. C, Proboscis neck. D, Anterior region of the collar. E, Anterior pharyngeal region of the trunk. bv, blood vessel; cv, cardiac vesicle; dm, dorsal mesentery; g, glomerulus; gb, gill bar; go, gonad; nc, nerve cord; pc, proboscis coelom; phd, periheamal diverticulum; pl, pharynx lumen; plm, proboscis longitudinal muscles; pv, proboscis vesicle; s, stomochord; sc, skeletal cornua; sk, skeletal keel; sp, skeletal plate; tlm, trunk longitudinal muscles. Scale bars A, B, D, E = 250 µm; C = 150 µm. External features: The proboscis is long and conical with a small groove in the posterior third of its length. The total length is estimated to be 1 cm . The length of the proboscis is 3 mm and the collar is 0.5 mm . In live material, the proboscis is white and the collar and trunk are salmon pink. Internal features ( Figure 6 ): The nerve fiber layer of the proboscis does not show any thickening along the dorsal midline. The proboscis coelom almost extends to the tip of the organ as a narrow cavity closely surrounding the proboscis complex ( Fig. 6A ). The ventral and dorsal septa are present and start in the posterior half of the proboscis. They are both continuous throughout the length of the organ. The circular muscle fiber layer is thinner than the nerve fiber layer. The longitudinal muscle fibers are arranged in about 6 concentric rings ( Fig. 6B ). The glomerulus extends over the tip of the stomochord and surrounds the entire proboscis complex. The cardiac vesicle is well developed and extends to the tip of stomochord. Its anterior half is filled with connective tissue. The stomochord has thick walls and a narrow lumen throughout its length. Its lumen presents a large ventral diverticulum, which is twice as big as the primary lumen and join each other at the beginning of the skeleton plate. The skeletal plate starts on the ventral side of the stomochord and the keel is obtuse and short. The two coelomic cavities in the neck are present and there is also one conspicuous left vesicle leading to the exterior by a left proboscis pore ( Fig. 6C ). Very few characters could be determined from the collar ( Fig. 6D ) and trunk ( Fig. 6E ) due to distortions in the sections. Only the few characters described below could be assessed. The dorsal mesentery of the collar is present, but it has been impossible to determine its extent, as for the presence and extent of the ventral one. An anterior neuropore may be present. The branchial portion of the pharynx is equal in size to the ventral portion or slightly larger. There is a pair of dorso-lateral gonads, which are not lobed. The ventro-lateral longitudinal muscles of the trunk are well developed ( Fig. 6E ). Etymology. We dedicate the name of this animal to Professor A. Richard Palmer, University of Alberta , who has greatly contributed to our understanding of the comparative morphology and development of Pacific Coast invertebrates.