Heterocarpus sibogae De Man , 1917, De Man, 1917

Jiang, Guo-Chen, Chan, Tin-Yam & Shih, Tung-Wei, 2014, Morphology of the first zoeal stage of three deep-water pandalid shrimps, Heterocarpus abulbus Yang, Chan & Chu, 2010, H. hayashii Crosnier, 1988 and H. sibogae De Man, 1917 (Crustacea: Decapoda: Caridea), Zootaxa 3768 (4), pp. 428-436: 432-435

publication ID

http://dx.doi.org/10.11646/zootaxa.3768.4.2

publication LSID

lsid:zoobank.org:pub:B26D8C16-B96C-47C5-AB46-DBE1B0586F26

DOI

http://doi.org/10.5281/zenodo.4901951

persistent identifier

http://treatment.plazi.org/id/4E6087B6-FFAF-FFA2-E79E-3AD6FB52FBBE

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scientific name

Heterocarpus sibogae De Man , 1917
status

 

Heterocarpus sibogae De Man, 1917  

( Fig. 3 View FIGURE 3 , Table 1 View TABLE 1 )

Size: CL, mean 0.41 mm (range 0.38–0.43 mm); BL, mean 1.88 mm (range 1.85–1.90 mm); TL, mean 2.28 mm (range 2.25–2.30 mm).

Carapace ( Figs. 3 View FIGURE 3 A, B, D): Dorsoventrally flattened; rostrum slightly curved and slender, longer than antennular peduncle; dorsal anterior and posterior processes present; anteroventral margin bearing strong pterygostomian spine and 1 distinct spine; eyes sessile.

Antennule ( Fig. 3 View FIGURE 3 E): Peduncle unsegmented, slender and bearing 1 small tubercle; exopod unsegmented with 1 spatulate seta and 3 terminal aesthetascs as well as 1 terminal plumose seta; endopod with 1 long plumose seta.

Antenna ( Fig. 3 View FIGURE 3 F): Peduncle unsegmented and with 1 distal spine; endopod unsegmented, with 1 long terminal plumose seta and 1 slender spine; exopod distally 6 -segmented, with 11 marginal plumose setae, 1 distolateral seta and inner tubercle.

Mandible ( Fig. 3 View FIGURE 3 G): Palp absent; incisor and molar processes well differentiated; with lacinia mobilis.

Maxillule ( Fig. 3 View FIGURE 3 H): Coxal endite with 7 (2 subterminal+ 5 terminal) setae; basial endite with 2 strong setae and 3 cuspidate setae; endopod unsegmented, with 2 subterminal setae and 3 terminal setae; exopod absent.

Maxilla ( Fig. 3 View FIGURE 3 I): Coxal endite bilobed with 9 + 4 setae; basial endite bilobed with 3 + 4 setae; endopod with 9 (3 + 2 + 1 + 1 + 2) setae; scaphognathite margin with 5 plumose setae.

First maxilliped ( Fig. 3 View FIGURE 3 J): Coxa with 4 setae; basis with 9 setae; endopod unsegmented with 3, 1, 2, 4 (1 subterminal+ 3 terminal) setae; exopod unsegmented with 4 long plumose natatory setae.

Second maxilliped ( Fig. 3 View FIGURE 3 K): Coxa with 1 seta; basis with 6 setae; endopod 4 -segmented with 2, 1, 2, 4 (1 subterminal+ 3 terminal) setae; exopod unsegmented with 5 long plumose natatory setae.

Third maxilliped ( Fig. 3 View FIGURE 3 L): Coxa without setae; basis with 4 setae; endopod 4 -segmented with 2, 1, 2, 4 (1 subterminal+ 3 terminal) setae; exopod unsegmented with 5 long plumose natatory setae.

Pereiopods: Absent.

Abdomen ( Fig. 3 View FIGURE 3 A, C): With 5 somites and without setae or spines.

Pleopods: Absent.

Uropods: Absent.

Telson   ( Fig. 3 View FIGURE 3 A): Subtriangular, posterior border with 7 + 7 setae, outermost 2 pairs only plumose on inner margin; bases of each seta except outermost one with row of minute spinules.

H. abulbus   H. hayashii   H. sibogae   H. ensifer   The morphology of larvae have been known in nine pandalid genera ( Atlantopandalus, Pike & Williamson 1964   [Z 1, Z 7; Z = Zoea]; Austropandalus, Thatje & Bacardit 2000   [Z 1 –Z 5]; Chlorotocus, Heegaard 1969   [Z 1]; Dichelopandalus, Lebour 1940   , Pike & Williamson 1964 [Z 1 –Z 6], Pandalina, Lebour 1940   , Pike & Williamson 1964 [Z 1 –Z 7, P = Post-larva]; Pandalus, Lebour 1940   , Pike & Williamson 1964 [Z 1 –Z 6]; Stylopandalus, Lebour 1940   [Z 1 –Z 9, P]; Plesionika, Landeira et al. 2009   [Z 1 –Z 5]; Heterocarpus, Iwata et al. 1986   , Landeira et al. 2010 [Z 1 –Z 5]). Common characters of pandalid larvae are: eye peduncle narrowed at base; carapace with two dorsal protuberances and anteroventral margin bearing spines, antennule with peduncle strongly concave and exopod bearing spatulate seta; antennal exopod segmented; rostrum well-developed since early stages (also see Thatje & Bacardit 2000, Landeira et al. 2010). For the first zoeal stage, however, there are no clear difference found amongst different pandalid genera.

With respect to the genus Heterocarpus   , the first zoeae of only two species were known, namely H. ensifer ( Landeira et al. 2010)   and H. sibogae ( Iwata et al. 1986)   . However, the description of H. sibogae   is rather brief and the present work re-describes the first zoea of this species in details. With the addition of H. abulbus   and H. hayashii   , the first zoeae of four species in this genus are now known. All of them share the common characters of anteroventral margin of carapace bearing spines, carapace with dorsomedian tubercles on anterior and posterior parts, and antennule with spatulate seta. On the other hand, the first zoeae of these four species can be readily distinguished by the following characters (also see Table 1 View TABLE 1 ):

(1) Spines on anteroventral margin of carapace: Other than the pterygostomian spine, H. sibogae   differs from the other three species in bearing only one additional spine at the anteroventral margin of carapace (vs. 2 spines in others). Heterocarpus abulbus   can also be separated from H. ensifer   and H. hayashii   in the one of the two additional spines at the anteroventral carapace being rather weak (both spines very distinct in H. ensifer   and H. hayashii   ).

(2) Body size and rostral length: The size of the zoea is much larger for H. abulbus   (body length 2.44 mm) as compared to the other three species (body lengths 1.93 mm, 1.89 mm, 1.88 mm in H. ensifer   , H. hayashii   and H. sibogae   , respectively). The rostrum of H. ensifer   is distinctly shorter than the other three species in only extending to the middle of the antennular peduncle (vs. reaching or overreaching distal margin of antennular peduncle).

(3) Appendage setation: The endopod of maxillule has three subterminal setae in H. ensifer   , whilst the other three species have only two subterminal setae. Heterocarpus abulbus   can be further separated from H. hayashii   and H. sibogae   in having two instead of one seta on the coxa of the second maxilliped. Moreoever, H. sibogae   has a somewhat different endopod setation at the second maxilliped (2, 1, 2, 4 vs. 3, 1, 2, 4– 5 in the other three species, see Table 1 View TABLE 1 ).

As in adults, the first zoeae of H. ensifer   , H. hayashii   and H. sibogae   are more similar than with H. abulbus   , which belongs to a different species group than the former three. On the other hand, although adults of H. ensifer   , H. hayashii   and H. sibogae   are rather similar, distinct differences are already present amongst the zoeae of these closely related species. All these suggested that larval characters can provide important insights to the understanding of the taxonomy and phylogenetic relationships amongst Heterocarpus   shrimps.

TABLE 1. Characteristics of the first zoeae in four species of Heterocarpus. a, aesthetascs; b, basal spines; c, cuspidate setae; d, distolateral setae; p, plumose setae; s, spatulate setae; t, strong setae; v, slender spines.

  (present study) (present study) (present study) (Landeira et al. 2010)
Carapace        
Length (mm) 0.53–0.58 0.38–0.45 0.38–0.43 about 0.42
Anteroventral spines Antennule 2 2 1 2
Peduncle Endopod Exopod setation Antenna (setation) 1 small tubercle long plumose seta 3a+1p+1s 1 small tubercle long plumose seta 3a+1p+1s 1 small tubercle long plumose seta 3a+1p+1s 2 small tubercles long plumose seta 3a+1p+1s
Peduncle Endopod Exopod Maxillule (setation) 1b 1p+1v 11p+1d 1b 1p+1v 11p+1d 1b 1p+1v 11p+1d 1b 1p+1v 11p+1d
Coxal endite Basial endite Endopod Exopod Maxilla (setation) 7 2t+3c 5 0 7 2t+3c 5 0 7 2t+3c 5 0 7 2t+3c 6 0
Coxal endite Basial endite Endopod Scaphognathite 1 Maxilliped (setation) 8+3 3+4 3,2,1,1,2 5p 8+3 4+4 3,2,1,1,2 5p 9+4 3+4 3,2,1,1,2 5p 9+4 5+5 3,2,1,1,2 5p
Coxal Basis Endopod Exopod 2 Maxilliped (setation) 5 11 3,1,2,4 4p 4 10 3,1,2,4 4p 4 9 3,1,2,4 4p 7 12 3,1,2,4 4p
Coxal Basis Endopod Exopod 3 Maxilliped (setation) 2 8 3,1,2,5 5p 1 9 3,1,2,5 5p 1 6 2,1,2,4 5p 1 9 3,1,2,4 5p
Coxal Basis Endopod Exopod 0 4 2,1,2,4 5p 0 4 2,1,2,4 5p 0 4 2,1,2,4 5p 0 4 2,1,2,4 5p
Discussion        

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Pandalidae

Genus

Heterocarpus

Loc

Heterocarpus sibogae De Man , 1917

Jiang, Guo-Chen, Chan, Tin-Yam & Shih, Tung-Wei 2014
2014
Loc

H. ensifer (

Landeira et al. 2010
2010
Loc

Plesionika

Landeira et al. 2009
2009
Loc

Austropandalus

Thatje & Bacardit 2000
2000
Loc

Heterocarpus

Iwata et al. 1986
1986
Loc

H. sibogae (

Iwata et al. 1986
1986
Loc

Chlorotocus

Heegaard 1969
1969
Loc

Atlantopandalus

Pike & Williamson 1964
1964
Loc

Dichelopandalus

Lebour 1940
1940
Loc

Pandalina

Lebour 1940
1940
Loc

Pandalus

Lebour 1940
1940
Loc

Stylopandalus

Lebour 1940
1940