Stage-I zoeae of laboratory-hatched 

 Lopholithodes mandtii (Decapoda, 

 Anomura, Lithodidae) 



Evan B. Haynes 



Auke Bay Laboratory, Alaska Fisheries Science Center 



National Marine Fisheries Service. NOAA 



1 1 305 Glacier Highway. Juneau Alaska 99801-8626 



Of the approximately 25 species of 

 Lithodidae of the northern North 

 Pacific Ocean, larvae have been de- 

 scribed, at least in part, for 11 

 species: Dermaturus mandtii 

 Brandt, Cryptolithod.es typicus 

 Brandt, Hapalogaster grebnitzkii 

 Schalfeew, H. mertensii Brandt, 

 Lithodes aequispina Benedict, 

 Paralithodes brevipes (Milne Edwards 

 and Lucas), P. camtschaticus 

 (Tilesius), P. platypus Brandt, 

 Placetron wosnessenskii Schalfeew, 

 Rhinolithodes wosnessenskii Brandt, 

 and Hapalogaster dentata (De Haan). 

 A review of the published descrip- 

 tions of these larvae, except H. 

 dentata, has been given by Haynes 

 ( 1984). In this paper I describe and 

 illustrate Stage-I zoeae of Lopho- 

 lithodes mandtii Brandt and com- 

 pare its morphology with the larvae 

 reviewed by Haynes and with the 

 published description ofH. dentata. 



Methods 



Zoeae were hatched in the labora- 

 tory by an ovigerous female col- 

 lected 4 April 1989 at Little Port 

 Walter, southern Baranof Island, 

 Alaska. The female was transported 

 to the Auke Bay Laboratory 14 April 

 1989 and kept in an aquarium with 

 running seawater. The zoeae began 

 hatching about 2 wk later and were 

 active swimmers, congregating near 

 the surface of the aquarium. About 

 25 of the hatched zoeae were pre- 

 served every 2 or 3d during 2-31 

 May 1989, until no zoeae remained 

 alive in the aquarium. No attempt 



was made to rear the zoeae. Water 

 temperatures in the aquarium were 

 5.6-6.5° C during collection of the 

 larvae. No prezoeae were seen. 

 None of the zoeae collected had 

 molted to Stage II and no morpho- 

 logical differences were noted 

 among the zoeae studied. 



Methods of measuring zoeae and 

 their appendages and techniques of 

 illustrations follow Haynes (1984). 

 Processes on the telson are num- 

 bered from the outermost to inner- 

 most ( medial ) pair. For clarity in the 

 illustrations, setules on plumose se- 

 tae and spinules on telsonal spines 

 are omitted, but spinulose setae are 

 shown. At least 5 zoeae were used 

 to verify segmentation and setation; 

 10 zoeae were used for carapace and 

 total length measurements. 



Description of zoeae 



Carapace (Fig. 1A,B) Mean 

 carapace length, 1.3mm (range 1.1- 

 1.5mm); mean total length (exclud- 

 ing telsonal processes), 5.7mm 

 (range 5. 1-6.0 mm). Carapace with 

 medially curved, long (>l/4 cara- 

 pace length) posterolateral spines, 

 and pronounced dorsal ridge. No su- 

 praorbital spines. Eyes sessile. 



Antennule (Fig. 1C) First an- 

 tenna (antennule) with unsegment- 

 ed tubular portion (peduncle) and 

 distal conical projection. Peduncle 

 with ventral plumose seta. Conical 

 projection with 5-6 aesthetascs and 

 a simple seta terminally and two 

 aesthetascs subterminally. 



Antenna (Fig. ID) Antenna with 

 endopod and scale. Endopod slightly 

 shorter than scale, and tipped with 

 two hook-like projections. Antennal 

 scale unsegmented, with fringe of 9 

 heavily plumose setae along termi- 

 nal inner margin and prominent 

 spine on distal outer margin. Ventral 

 surface of protopodite with spinulose 

 spine at base of endopod and naked 

 spine at base of antennal scale. 



Mandibles (Fig. IE) Incisor pro- 

 cess of right and left mandibles 

 tooth-like with minute serrations. 

 Right mandible: anterior margin 

 with small teeth and denticulated 

 projection; dorsal margin of molar 

 with two denticular ridges; posterior 

 margin with two denticulated pro- 

 jections. Left mandible: anterior 

 margin with premolar denticles. 

 Mandibles without subterminal pro- 

 cesses, movable premolar denticle, 

 palp, or palp bud. 



Maxillule (Fig. IF) Endopod 3- 

 segmented, with 3 setae terminally, 

 long distal seta on second segment, 

 and short distal seta on 1st seg- 

 ment; coxal endite unsegmented 

 with 4 plumodenticulate setae and 

 3 setae subterminally that some- 

 times have either a few minute 

 spinules or setules; basal endite 

 with 2 elongate, spinelike teeth 

 armed with small denticles and 2 

 naked setae subterminally; no fine 

 hairs on maxillule. 



Maxilla (Fig. 1G) Endopod bi- 

 lobed, setation formula 3,1,3; basal 

 and coxal endites bilobed; coxal 

 endite with 7 (sometimes 6) termi- 

 nal and 1 subterminal setae on 

 proximal lobe, 3 terminal and 1 sub- 

 terminal setae on distal lobe, basal 

 endite with 4 terminal and 1 sub- 

 terminal setae on proximal lobe and 



3 terminal and 1 subterminal setae 

 on distal lobe; scaphognathite with 



4 long, marginal plumose setae; fine 



Manuscript accepted 2 February 1993. 

 Fishery Bulletin, U.S. 91:379-381 (1993). 



379 



